Research suggests that the pressure of being timed may interfere with performance on tests that involve mathematical problems. A fictional study was conducted with 30 sixth graders. First, the sixth graders were given a math test that contained 50 problems and were told that they had only one hour to complete it (timed condition). The same sixth graders were later given a math test that contained 50 problems and were told that they could have as much time, as needed, to complete the test (unlimited time condition). The total number of correct answers for each sixth grader was then calculated for each condition. Then, for each student, the difference between the two scores (timed − untimed) was calculated. The researchers hypothesized that the sixth graders would get fewer correct answers when they took the test with a time limit than when they had unlimited time. If μ1and μ2 represent the number of correct answers during the timed condition and the unlimited time condition, respectively, and let μd be the mean of the differences in the number of correct answers (timed − untimed) of all sixth graders. Which of the following are the appropriate null and alternative hypotheses? H0: μd = 0 Ha: μd > 0 B. H0: μd = 0 Ha: μd < 0 C. H0: μd < 0 Ha: μd = 0 D. H0: μ1 − μ2 = 0 Ha: μ1 − μ2 < 0

Answer:

Heres the truth.

Step-by-step explanation:

If you haven't learned anything and you need to do a DBA. Just tell your teacher this, "Even though I've completed the Module... I still don't fully understand the concepts throughout the module. Is there anyway you can help me go over, review, and workout specific things that i understand and don't understand?"

It's best to actually do the work instead of submiting questions for others to answer on here. You should ask for help from a teacher, or go to the online tutoring.

Answer: [tex]\dfrac{3}{10}[/tex]

Step-by-step explanation:

Let A be the event of getting a factor of 15 when a fair spinner numbered 1 - 5 spins and B be the event that a fair coin is tossed.

The factors of 15 = [tex]1,\ 3,\ 5[/tex]

Then ,the probability of obtaining a factor of 15 is given by :-

[tex]P(A)=\dfrac{3}{5}[/tex]

The probability of getting a tail :-

[tex]P(B)=\dfrac{1}{2}[/tex]

Since both the events are independent , thus

The probability of obtaining a factor of 15 and a tail is given by :-

[tex]P(A)\times P(B)\\\\=\dfrac{3}{5}\times\dfrac{1}{2}=\dfrac{3}{10}[/tex]

Hence, the required probability : [tex]\dfrac{3}{10}[/tex]

Answer:

By continuing my education I increased my earning potential from $21,484 to $39,746 a year. That's a difference of $18262 a year.

If the additional education costs $18,000, then in one year it will pay for itself.

Answer:

The answer is 1 year.

Step-by-step explanation:

You increased your yearly earning potential from $21,484 to $39,746.

The difference is : [tex]39746-21484=18262[/tex] dollars

This difference is in a year.

So, if the additional education costs $18,000, then in about 1 year it will pay for itself.

Hence, the answer is 1 year.

Answer:

6

Step-by-step explanation:

The 8 is the leading coefficient, the -7 is the linear term, and the 6 is the constant.

Answer:

the constant term is 6.

Second option is correct.

Step-by-step explanation:

The quadratic function is [tex]f(x)=8x^2-7x+6[/tex]

The general form of a quadratic function is [tex]y=ax^2+bx+c[/tex]

Here c is the constant term and a can't be zero.

On comparing the given equation with the general form, we get

a = 8

b = -7

c = 6

Therefore, the constant term is 6.

Second option is correct.

Answer:

downtown workers

Step-by-step explanation:

The research group should do the survey with downtown workers in order to find the opinions for the construction of a new downtown parking garage in downtown. Since the workers need to commute to downtown for work by various modes such as buses, private vehicles, bicycles, taxis, share vehicles, etc., therefore the the research group will get maximum useful information from the downtown workers for the construction of a new parking garage.

Thus, option "downtown workers" is correct.

The population of the survey would be the city residents.

The population of the survey would be the city residents. The research group wants to find the opinions of the city residents on the construction of a new downtown parking garage. While downtown shoppers, visitors, and workers could provide valuable insights, the opinions of the city residents would be the most relevant and encompassing for understanding the overall impact of the new downtown parking garage.

#SPJ12

Answer:

D

Step-by-step explanation:

15-x=4

Subtract 15 from both sides

leaves you with

-x=-11

x=11

Hey there! :)

15 - x = 4

Subtract 15 from both sides.

-x = 4 - 15

Simplify.

-x = -11

Divide both sides by -1.

-x ÷ -1 = -11 ÷ -1

x = 11

Therefore, your answer is D. 11

~Hope I helped! :)

Answer:

Ntoine and Tess have a disagreement over how to compute a 15% gratuity on $46.00.

This in real becomes :

[tex]0.15\times46=6.90[/tex] dollars

But, Tess  says, "It is easy to find 10% of 46 by moving the decimal point one place to the left to get $4.60. Do that twice. Then add the two amounts to get $4.60 + $4.60 = $9.20

So, Tess is wrong. Rather she should have done 10% of $46 giving $4.6 and then half of 4.6 that is 2.3 dollars. Getting a total of [tex]4.6+2.3=6.9[/tex] dollars which is the real amount.

Answer:

Ntoine and Tess have a disagreement over how to compute a 15% gratuity on $46.00.

This in real becomes :

dollars

But, Tess  says, "It is easy to find 10% of 46 by moving the decimal point one place to the left to get $4.60. Do that twice. Then add the two amounts to get $4.60 + $4.60 = $9.20

So, Tess is wrong. Rather she should have done 10% of $46 giving $4.6 and then half of 4.6 that is 2.3 dollars. Getting a total of  dollars which is the real amount.

Step-by-step explanation:

trust me

Answer:

The determinant is 15.

Step-by-step explanation:

You need to calculate the determinant of the given matrix.

1. Subtract column 3 multiplied by 3 from column 1 (C1=C1−(3)C3):

[tex]\left[\begin{array}{ccc}-25&-23&9\\0&3&1\\-5&5&3\end{array}\right][/tex]

2. Subtract column 3 multiplied by 3 from column 2 (C2=C2−(3)C3):

[tex]\left[\begin{array}{ccc}-25&-23&9\\0&0&1\\-5&-4&3\end{array}\right][/tex]

3. Expand along the row 2: (See attached picture).

We get that the answer is 15. The determinant is 15.

Answer:

The answer is 15

Step-by-step explanation:

Answer:

Option D RX=4 units

Step-by-step explanation:

we know that

In the right triangle RTS

The cosine of angle TRS is equal to

cos(TRS)=RT/RS

substitute

cos(TRS)=6/9 -----> equation A

In the right triangle RTX

The cosine of angle TRX is equal to

cos(TRX)=RX/RT

substitute

cos(TRX)=RX/6 -----> equation B

∠TRS=∠TRX -----> is the same angle

Match equation A and equation B

6/9=RX/6

RX=6*6/9=4 units

Answer:

(140, 37)

Step-by-step explanation:

If we are looking for the point where the 2 companies charge the same amount, we need to set the 2 cost function equal to each other and solve for the number of miles that makes the cost the same.  The number of miles will also be the same at this cost.  That means we need cost functions for each.  x is the number of miles that is driven, our independent variable.  If A-1 charges .10 per mile, the expression is .1x.  If the flat fee is 23, regardless of how many miles you drive, you can expect to pay

y = .1x + 23

If EZ charges .05 per mile, the expression is .05x.  If the flat fee is 30, regardless of how many miles you drive, you can expect to pay

y = .05x + 30

If we want to see where the cost functions are equal, we set the right sides of those equations equal to one another and solve for the number of miles that makes the cost the same.

.1x + 23 = .05x + 30 and

.05x = 7 so

x = 140 miles.

In order to find the cost we will pick one of the equations and sub in 140 for x and solve for y.

y = .1(140) + 23

y = 14 + 23

y = 37

The coordinate pair is (140 miles, $37)

This means that at 140 miles driven, the cost is $37 no matter which rental agency you choose.

Answer:

Step-by-step explanation:

The volume of a cylinder is given by ...

  V = Bh . . . . . where B is the base area and h is the height

The volume of a pyramid or cone is given by ...

  V = (1/3)Bh . . . . . where B is the base area and h is the height

The area of a square of side length s is ...

  A = s²

The area of a circle of radius r is ...

  A = πr²

___

Using these formulas, the volumes of these objects are ...

  cylinder: (9π in²)(10 in) = 90π in³

  square pyramid: (1/3)(4 in)²(7 in) = 37 1/3 in³

  cone: (1/3)(π(2.5 in)²)(6 in) = 12.5π in³ . . . . slightly larger than the pyramid

Answer:

12.5

Step-by-step explanation:

Answer:

2÷ 4

Step-by-step explanation:

Quotient means division

2÷ 4

Answer:

Is there supposed to be a photo

Step-by-step explanation:

Answer:

  b.  x^2 +2cx +bc+ac-ab = 0

Step-by-step explanation:

It's a matter of what I would describe as tedious algebra. You have to multiply by the least common denominator, then simplify to standard form.

After multiplying the equation by (x+a)(x+b)(x+c) and subtracting the right side, you have ...

  (x +b)(x +c) +(x +a)(x +c) -(x +a)(x +b) = 0

Expanding each factor pair gives ...

  (x² +(b+c)x +bc) +(x² +(a+c)x +ac) -(x² +(a+b)x +ab) = 0

Collecting terms gives ...

  x²(1 +1 -1) +x(b+c +a+c -a -b) +(bc +ac -ab) = 0

  x² +2cx +bc +ac -ab = 0 . . . . . matches selection B

The greatest number of students that could be in each row is 12, which is the greatest common divisor of 36 and 120. The color guard will have 3 rows, and the high school marching band will have 10 rows.

To determine the greatest number of students that could be in each row and the number of rows each group will have, we need to find the greatest common divisor (GCD) of the two numbers representing the members in each group, 36 and 120. The greatest common divisor is the largest number that divides both numbers without leaving a remainder. Calculate this by listing the factors of each number or using the Euclidean algorithm.

Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36

Factors of 120: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120
The greatest common divisor is the largest factor both numbers share, which is 12. Therefore, the greatest number of students per row is 12.

Now, to find the number of rows for each group, divide the total number of members in each group by the number of students per row:

So, there will be 3 rows of color guard members and 10 rows of marching band members.

Problem: Same y intercept as x+4y=16, through (4,5)

Y intercept is when x=0 so 4y=16, y=4, y intercept (0,4)

Slope of line through (0,4) and (4,5) is change in y over change in x,

m = (5 - 4)/(4 - 0) = 1/4

Answer: slope 1/4

Check:

The new line is y = (1/4) x + 4

because the y intercept is still (0,4)

Let's check it's through (4,5)

(1/4) (4) + 4 = 5 check

Answer:

Step-by-step explanation:

The slope-intercept form of an equation of a line:

[tex]y=mx+b[/tex]

m - slope

b - y-intercept

The formula of a slope:

[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]

========================================

We have:

[tex]f(x)=3x+6\to m_f=3[/tex]

From the table:

[tex](1,\ 3),\ (2,\ 6)\\\\m_g=\dfrac{6-3}{2-1}=\dfrac{3}{1}=3[/tex]

[tex]m_f=m_g=3[/tex]

Answer:

1st one

Step-by-step explanation:

Answer:

Step-by-step explanation:

h(0) = -.01·0² +3·0 = 0 . . . . . the height when the ball was hit

The function can be factored as ...

  f(d) = -0.01d(d -300)

This has zeros at d=0 and d=300, so the maximum will be halfway between, at d=150.

  f(150) = -0.01·150(150 -300) = -1.5(-150) = 225

The height of the ball when hit was 0 feet, and the ball reached a maximum height of 225 feet.

Bryan hits a golf ball whose path is given by the function f(d) = -0.01d2 + 3d, where d is the distance the ball travelled in feet and f(d) is the height of the ball. The height of the golf ball when it was hit was feet and the ball reached a maximum height of feet.

Answer:

[tex]f: (0,1) \to \mathbb{R}[/tex]

[tex]f(x) = \sin(1/x)[/tex]

Step-by-step explanation:

f is continuous because is the composition of two continuous functions:

[tex]g(x) = \sin(x)[/tex] (it is continuous in the real numbers)

[tex]h(x) = 1/x[/tex] (it is continuous in the domain (0,1))

It is bounded because [tex]-1 \leq \sin(\theta) \leq 1[/tex]

And it is not uniformly continuous because we can take [tex]\varepsilon = 1[/tex] in the definition. Let [tex] \delta > 0[/tex] we will prove that there exist a pair [tex]x,y\in \mathbb{R}[/tex] such that [tex]|x-y|< \delta[/tex] and [tex]|f(x) -f(y)|> \varepsilon = 1[/tex].

Now, by the archimedean property we know that there exists a natural number N such that

[tex] \frac{1}{N} < 2\pi \delta[/tex]

[tex]\Rightarrow \frac{1}{2\pi N} < \delta[/tex].

Let's take [tex]x = \frac{1}{2\pi N + \pi/2}[/tex] and [tex]y = \frac{1}{2\pi N + 3\pi/2}[/tex]. We can see that

[tex]|x-y| = \frac{1}{2\pi N + \pi/2}-\frac{1}{2\pi N + 3\pi/2}<\frac{1}{2\pi N} <\delta[/tex]

And also:

[tex]|f(x)- f(y)| = |f(2\pi N + \pi/2) - f(2\pi N + 3\pi/2)| = |1 - (-1)| = 2 > \varepsilon[/tex]

And we conclude the proof.

Answer:

True

Step-by-step explanation:

The binomial distribution that has a probability of success equal to .20, would be left skewed for sample size of 20.

The given statement "The binomial distribution that has a probability of success equal to .20 would be left skewed for sample size 20" is false.

The statement is incorrect. The binomial distribution with a probability of success equal to 0.20 and a sample size of 20 would not necessarily be left-skewed. The shape of the binomial distribution depends on the values of the probability of success and the sample size.

In general, for a binomial distribution with a small probability of success (such as 0.20) and a large sample size (such as 20), the distribution tends to approximate a normal distribution. As the sample size increases, the binomial distribution becomes more symmetric and bell-shaped.

Therefore, it is not accurate to claim that the binomial distribution with a probability of success equal to 0.20 and a sample size of 20 would be left-skewed.

To know more about binomial distribution:

https://brainly.com/question/33656163

#SPJ2

Answer:

  5/12

Step-by-step explanation:

The fraction that is girls is the ratio of girls to the total of boys and girls:

  girls/(boys+girls) = 5/(7+5) = 5/12

How many households is 463 households

Answer:

C

Step-by-step explanation:

Just got it right.

Answer:

  1050 g < weight ≤ 1150 g

Step-by-step explanation:

Let w represent the weight of the package in grams. The the number of 100-gram increments after the first 250 grams is given by ...

  ⌈(w-250)/100⌉ . . . . . . . where ⌈ ⌉ signifies the ceiling function

and the charges for a package exceeding 250 grams will be ...

  0.65 + 0.10⌈(w -250)/100⌉ = 1.55

  0.10⌈(w -250)/100⌉ = 0.90 . . . . . . . . subtract 0.65

  ⌈(w -250)/100⌉ = 9 . . . . . . . . . . . . . . . divide by 0.10

  8 < (w-250)/100 ≤ 9 . . . . . . . . . . . . . . meaning of ceiling function

  800 < w -250 ≤ 900 . . . . . . . . . . . . . multiply by 100

  1050 < w ≤ 1150 . . . . . . . . . . . . . . . . . add 250

The weight in grams could be greater than 1050 and at most 1150 for a charge of $1.55.

Answer:

Period=6

Step-by-step explanation:

Given:

t=1cos(1.05h)+37

Using acos(bx-c)+d to find the period of the given function

amplitude= a

period= 2π/Bb

phase shift=c (positive is to the left)

vertical shift=d

comparing with t=1cos(1.05h)+37, we get

a=1

b=1.05

c=0

d=37

period= 2π/b

          =2π/1.05

          =5.983

          =6

Period of function is 6, after every 6 hours the refrigerator sensor will reach its maximum temperature and the cycle will move towards reducing temperature i.e it'll reach the minimum temperature then again the cycle will move upwards raising the temperature to maximum and so one period will be completed!

Answer:

6

Step-by-step explanation:

Felicity set the thermostat of her refrigerator to 37°F. The refrigerator temperature t in degrees Fahrenheit h hours after the temperature sensor in the refrigerator is activated satisfies t=1cos(1.05h)+37. Therefore, the period of the function is 6.

Answer:

(s-6)/r

option D

Step-by-step explanation:

The slope-intercept form a line is y=mx+b where m is the slope and b is the y-intercept.

Compare y=mx+b and y=cx+6, we see that m=c and c is the slope.

Now we are also given that (r,s) is on our line which means s=c(r)+6.

We need to solve this for c to put c in terms of r and s as desired.

s=cr+6

Subtract 6 on both sides:

s-6=cr

Divide both sides by r:

(s-6)/r=c

The slope in terms of r and s is:

(s-6)/r.

Answer:

  one real root: n ≈ 2.38450287889

Step-by-step explanation:

My favorite solution method for higher-degree polynomials is to use a graphing calculator.

Descartes' rule of signs tells you the one sign change among coefficients means there will be one positive real root. A graph shows you it is about 2.4, hence irrational (not a divisor of 33, so not rational).

You can use a cubic formula to find an explicit expression for the root, or you can find its value using any of several iteration methods. The attachment shows Newton's method iteration being used to refine the graph value of 2.385 to the more accurate 2.38450287889.

__

Factoring that root from the cubic results in a quadratic with irrational coefficients. Its vertex form is approximately ...

  y = (n +2.692)² + 6.591

Hence, the complex roots will be near -2.692±i√6.591.

_____

There are formulas for the roots of a cubic. The formula tells you the real root for this cubic is ...

  n = 2√(2/3)cosh(1/3·arccosh(24√(3/2))) -1 ≈ 2.38450287889

[tex](5ab)^{\tfrac{3}{2}}=\sqrt{(5ab)^3}=\sqrt{125a^2b^3}[/tex]

Answer:

¼ yd

Step-by-step explanation:

2/5 - 3/20

1. Find the lowest common denominator of the two fractions.

The LCD of 5 and 20 is 20.

2. Give the fractions the same LCD

2/5 - 3/20 = 8/20 - 3/20

3. Subtract the numerators

Keep the same denominator.

8/20 - 3/20 = 5/20

4. Simplify the fraction

5/20 = ¼  

The beetle crawled ¼ yd further than the spider.