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Which model accurately represents the chemical equation 2H2 + O2è 2H2O?

Answer:

2x

Step-by-step explanation:

Cost of x articles at 2 dollars each = 2x

Answer:

The probability that a randomly selected student has dark hair, given that the student has blue eyes is 43%.

Step-by-step explanation:

Conditional probability:

Let A and B any two events connected to a given random experiment E. The conditional probability of the event A on the hypothesis that the event B has occurred, denoted by P(A|B), is defined as

[tex]P(A|B)=\frac{P(A\cap B)}{P(B)}[/tex]

Given that,

In a city school, 70% of students have blue eyes, 45% have dark eyes and 30% have blue eyes and dark hair.

A= students have blue eyes

B= Students have dark hair.

P(A)= 70% [tex]=\frac{70}{100}[/tex] [tex]=\frac7{10}[/tex]

P(B)=45% [tex]=\frac{45}{100}[/tex] [tex]=\frac9{20}[/tex]

P(A∩B)=30%[tex]=\frac{30}{100}[/tex] [tex]=\frac3{10}[/tex]

∴P(B|A)

[tex]=\frac{P(A\cap B)}{P(A)}[/tex]

[tex]=\frac{0.3}{0.7}[/tex]

[tex]=\frac37[/tex]

=0.429

=0.429×100 %

≈43%

The probability that a randomly selected student has dark hair, given that the student has blue eyes is 43%.

Answer:

millimeter

Step-by-step explanation:

1/1000

Final answer:

The area of a 3in by 3in square is calculated by squaring the side length. The area is 9 square inches.

Explanation:

The area of a 3in by 3in square can be calculated by multiplying the length of one side by the length of another side since the sides are equal in a square. In this case, both sides measure 3 inches.

The formula for the area of a square is:

Area = side × side

Applying the formula for our 3in by 3in square:

Area = 3in × 3in = 9 square inches

This straightforward calculation represents how the surface area of a square object changes when the sides of the square are altered. When the sides of a square are scaled down by a fraction, the area changes by the square of that fraction (e.g., scaling down by 3/4 leads to an area that is 9/16 of the original).

Answer:

450 square feet

Step-by-step explanation:

Think of the shape as a complete rectangular

The area of the rectangular shape would be 25×30 = 750 square feet

Now find the area of the missing space and subtract it from 750

it would be 15×20 = 300 square feet

750 - 300 = 450 square feet

Answer:

0.2027 is the probability that exactly 3 out of 9 adults use their smartphones in meetings or classes.

Step-by-step explanation:

We are given the following information:

We treat adult using smartphones in meetings or classes as a success.

P(Adult using smartphone) = 46% = 0.46

Then the number of adults follows a binomial distribution, where

[tex]P(X=x) = \binom{n}{x}.p^x.(1-p)^{n-x}[/tex]

where n is the total number of observations, x is the number of success, p is the probability of success.

Now, we are given n = 9

We have to evaluate:

[tex]P(x = 3)\\\\= \binom{9}{3}(0.46)^3(1-0.46)^6\\\\= 0.2027[/tex]

0.2027 is the probability that exactly 3 out of 9 adults use their smartphones in meetings or classes.

Final answer:

To find the probability that exactly 3 of the 9 randomly selected adult smartphone users use their smartphones in meetings or classes, we can use the binomial probability formula.

Explanation:

To find the probability that exactly 3 of the 9 randomly selected adult smartphone users use their smartphones in meetings or classes, we can use the binomial probability formula. The binomial probability formula is given by:

P(X=k) = C(n,k) * p^k * (1-p)^(n-k)

where:

P(X=k) is the probability of getting exactly k successes

C(n,k) is the combination formula

p is the probability of success (46% in this case)

n is the total number of trials (9 in this case)

Plugging in the values, we get:

P(X=3) = C(9,3) * (0.46)^3 * (1-0.46)^(9-3)

P(X=3) = 84 * (0.46)^3 * (0.54)^6

P(X=3) = 0.299 (rounded to three decimal places)

Answer:

6x-76

Step-by-step explanation:

If you graph it out, you'll realize it makes a line that cuts the y-intercept at -76, thus the last value. The slope also has a gradient of 6, thus the coeffecient of x.

Final answer:

The slope of the line through the points given is 6, calculated using the slope formula with the rise over run between the two points.

Explanation:

The slope of a line is calculated by finding the ratio of the vertical change (the rise) to the horizontal change (the run) between two points on the line. Using the coordinates provided (12, -4) and (15, 14), we can apply the slope formula slope (m) = (y_2 - y_1) / (x_2 - x_1). Plugging in the values gives us (14 - (-4)) / (15 - 12) = 18 / 3 = 6. Therefore, the slope of the line that contains these points is 6.

1200 ml  of water needs to be added to lower it to a 2% solution.

Step-by-step explanation:

Given that,

A scientist has 400ml of a 8% solution.

you need to find how water is required to lower the 400 ml to 2% solution.

Let 'x' be the amount of water added to lower it 2% solution.

The formula is given by,

volume of the liquid × % of solution = volume of the new liquid × new %

This can be denoted in chemical relationship ⇒ c₁v₁=c₂v₂ where c is concentration and v is volume .

Now, to find the total volume of new liquid in ml :

400 ml = v₁

0.08= c₁  

0.02=c₂

v₂=?

400 × 0.08 =v₂ × 0.02

v₂=1600 ml

To find the x value :

Amount to be added = volume of new liquid - volume of liquid before.

⇒ x =1600-400

⇒ x =1200 ml

∴ 1200 ml of water needs to be added to lower it to a 2% solution.

Answer:

Correct option: (d) 7.

Step-by-step explanation:

Let the number be denoted by x.

The original fraction is: [tex]\frac{29}{62}[/tex]

Add x to the numerator, i.e. 29 and subtract 2x from the denominator, i.e. 62.

The new fraction is: [tex]\frac{29+x}{62-2x}[/tex]

Now equate the new fraction to [tex]\frac{3}{4}[/tex] and solve for x as follows:

     [tex]\frac{29+x}{62-2x}=\frac{3}{4}[/tex]

[tex]4(29+x)=3(62-2x)\\116+4x=186-6x\\4x+6x=186-116\\10x=70\\x=7[/tex]

The value of x is 7.

Thus, the correct option is (d).

Final answer:

To find the probability that the sample mean is between two hours and three hours, calculate the z-scores and use the z-table to find the probability.

Explanation:

To find the probability that the sample mean is between two hours and three hours, we need to calculate the z-scores corresponding to these values and use the z-table to find the probability.

First, we calculate the z-score for two hours:

z = (2 - 2.5) / (0.25 / sqrt(60)) = -3.16

Next, we calculate the z-score for three hours:

z = (3 - 2.5) / (0.25 / sqrt(60)) = 3.16

Using the z-table, we find that the probability of getting a z-score between -3.16 and 3.16 is approximately 0.9986. Therefore, the probability that the sample mean is between two hours and three hours is approximately 0.9986.

]

Answer:

fraction which has a terminating decimal as its decimal expansion is:

1/5

Step-by-step explanation:

We are given 4 fractions:

1/3 , 1/5 , 1/7 and 1/9

We have to find which fraction has terminating decimal.

1/3 = 0.33333...

1/5 = 0.2

1/7 = 0.142857142857...

1/9 =0.11111.....

Hence, fraction which has a terminating decimal as its decimal expansion is:

1/5

Final answer:

A fraction will have a terminating decimal if its denominator is a power of 2, a power of 5, or a combination of both since the base of our number system is 10. Examples like 1/8 and 5/16 have terminating decimals because their denominators are powers of 2.

Explanation:

A fraction will have a terminating decimal expansion if its denominator can be written in the form 2n5m, where n and m are nonnegative integers. This is because the base of our number system is 10, which is 2×5. So any fraction with a denominator that is a factor of a power of 10 will have a terminating decimal expansion.

Example:

In contrast, a fraction like 1/3 does not have a prime factorization that matches the form 2n5m and therefore has a non-terminating decimal expansion (0.333...).

Answer:

= 1700 :)

Step-by-step explanation:

-multiply all the sides,

-add them,

- then double the answer (or times it  by 2):

1) 30 times 20 = 600

30 times 5= 150

20 times 5 =100

2) Add them:

600+150+100 = 850

then times 850 by 2

850 times 2 = 1700

Hope that helped :)

Answer:

Guys for this one the 30, 20, 5 is 1700

Step-by-step explanation:

Ok i'm so sorry but if you could answer this for me? nobody else will! >0<

Enter the equation of the circle described below.

Center (-3, 0), radius /5

Answer:(X+3)^2 +y^2 =25

This is the correct answer, i just found it out

Answer:

-5x - 3x = 16

-8x = 16

x = -2

y = x

Step-by-step explanation:

Answer:

(-2, -2)

Step-by-step explanation:

Make use of the 2nd equation to eliminate x or y in the 1st equation:

-5x - 3(x) = 16

Then -8x = 16, and x = -2.  Since we are told that y = x, y = -2.

The solution is (-2, -2).

Answer:

(4+x)(5+x)(5+x) = 700

x^3 + 14x^2 + 65x + 100 = 700

x^3 + 14x^2 + 65x - 600 = 0

x = 4.225

rounding = 4.23

Step-by-step explanation:

Answer:

1:2

 2:1

2:3

Step-by-step explanation:

3:6

Divide each side by 3

3/3: 6/3       1:2

10:5

Divide each side by 5

10/5 : 5/5      2:1

16:24

Divide each side by 8

16/8: 24/8     2:3

The total number of possible New York license plates is 17,576,000.

The number of different license plates possible for a standard configuration in New York, where a license plate is composed of 3 digits followed by 3 letters, can be determined through combinatorial math.

Step-by-Step Solution:

Answer:

D. [0,pi/2]

Step-by-step explanation:

when Ф = 0 in radian

r²=  4cos (2(0))

r² = 4 * 1

r² = 4

∴ r = √4 = 2

r = 2.

when Ф = π/2 in radian

r²=  4cos (2(π/2))

r² = 4 * -1

r² = -4

∴ r = 0

Answer: 7/25 or 0.28

Step-by-step explanation:

Given that 7/15 play a sport and 3/5 play a musical instrument.

The probability that a NCVPS student play a sport AND a musical instrument means multiplication of the two probabilities

7/15 × 3/5 = 21/75 = 7/25

In hypothesis testing for this scenario, the null hypothesis (H-0) is that the proportion of rejected screens remains 12 percent (H-0: p = 0.12). The alternative hypothesis (Ha) is that the proportion of rejected screens is less than 12 percent (Ha: p < 0.12). A sample is taken and a significance test (such as a z-test for proportion) is conducted to decide if the null hypothesis can be rejected.

The question is looking for you to conduct a hypothesis test to investigate whether a new process in manufacturing cell phone screens has led to a reduced proportion of rejected screens. When conducting such a hypothesis test, you'll need to consider a null hypothesis and an alternative hypothesis.

The null hypothesis (H-0) is often the initial claim about a population proportion. In this case, the null hypothesis would be that 12 percent of the screens (0.12) are still being rejected: H-0: p = 0.12.

The alternative hypothesis (Ha) is what you might believe to be true if the null hypothesis is proven to be incorrect. Here, the alternative hypothesis would be that less than 12 percent of screens are being rejected with the new process: Ha: p < 0.12.

To clarify, if the new process is effective, a lower proportion of screens should be rejected. Thus, the hypotheses to be tested are:

Lastly, after selecting the sample, compute the sample proportion. Here a total sample size of 100 screens with only 6 being rejected means the sample proportion (p) = 6/100 = 0.06.

From here, you would proceed to conduct a significance test (possibly a z test for proportion) and determine a p-value to make a decision regarding the null hypothesis.

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Answer:

7.9617

Step-by-step explanation:

r=c/2pi so 50/2(3.14)

Answer: about 7.9617 !

Step-by-step explanation: you to divide 50 by 3.14 to get the diameter, then divide the diameter by 2 to get the radius, then round it!

Step-by-step explanation:

It is a right angled triangle so with reference angle 37°

hypotenuse (b) = 10

perpendicular (p) = x

So

tan 37° = p/ b

0.75 = x / 10

x= 0.75/10

Therefore x = 0.075

Hope it will help you :))

Answer:

x2-x1/y2-y1

-2--2/3-9=-2+2/3-9

=0/-3

Answer:

About 11.31

Step-by-step explanation:

a^2 + b^2 = c^2

4^2 + b^2 = 12^2

16    + b^2 = 144

-16                  -16

b^2 = 128

Take the square root of both sides

b= approximately 11.31

Answer:

P(Q or C) = 0.25

Step-by-step explanation:

We are given the following in the question:

Letters:

A, C, Q, U, A, I, N, T, A, N, C, E

Total number of observations, n  = 12

We have to find the probability that a randomly selected letter is Q or C.

Formula:

[tex]\text{Probability} = \displaystyle\frac{\text{Number of favourable outcomes}}{\text{Total number of outcomes}}[/tex]

P(Q or C) =

[tex]=\dfrac{\text{n(Q or C)}}{n} = \dfrac{3}{12} =0.25 = 25\%[/tex]

Thus,

P(Q or C) = 0.25

Answer:

x=2

Step-by-step explanation:

1 + 4x = -5 + 7x

Subtract 4x from each side

1 + 4x-4x = -5 + 7x-4x

1 = -5+3x

Add 5 to each side

1+5 = -5+5+3x

6 = 3x

Divide each side by 3

6/3 = 3x/3

2 =x

Answer:

Compound Interest Formula Solved For Rate:

log (1 + rate) = {log(total) -log(Principal)} ÷ Years

log (1 + rate) = {log(5,800) -log(5,000)} ÷ 5

log (1 + rate) = [3.7634279936 -3.6989700043] / 5

log (1 + rate) = 0.0644579893  / 5

log (1 + rate) = 0.0128915979

Then we raise 10 to the power of 0.0128915979  which equals

1.0301289629  = 1 + rate

Therefore, rate = .0301289629  and we multiply by 100 to make a percentage:

3.01289629 %

Source: https://1728.org/compint2.htm

https://1728.org/compint.htm

Step-by-step explanation:

Using the compound interest formula and the provided values, the interest rate for Mr Tan's investment is calculated to be approximately 3.02%.

The subject problem belongs to the topic of Compound Interest in mathematics. The formula used for compound interest is A = P (1 + r/n)^(nt), where A represents the total amount received, P represents the principal (initial investment amount), r represents the rate of interest, n represents the number of times interest is compounded per time period, and t represents the time period.

In this problem, Mr Tan's initial investment, P, is $5000. The total amount, A, he received after 5 years is $5800. The interest is compounded annually meaning that n is 1. We rearrange the compound interest formula to solve for the interest rate: r = [(A/P)^(1/nt) - 1]n .

Using Mr Tan's values, the calculation becomes: r = [(5800/5000)^(1/5) - 1]*1. Thus, the interest rate is approximately 0.0302 or 3.02%.

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Answer:

No, because when j = 8, the values of the expressions are different.

for a shorter answer, A

Step-by-step explanation:

No, because when j = 8, the values of the expressions are different. Therefore, option A is the correct answer.

An expression is a combination of terms that are combined by using mathematical operations such as subtraction, addition, multiplication, and division.

The given expression is 7(j-2)4j-5.

Here, j=3 ad j=8

When j=3, we have

7(3-2)4×3-5

= 7×1×4×3-5

= 84-5

= 79

When j=8, we have

7(8-2)4×8-5

= 7×5×4×8-5

= 1115

Therefore, option A is the correct answer.

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Answer:

The median is - C

The minimum is - A

The maximum is - E

The lower quartile (Q1) is - B

The upper quartile (Q3) is - D

The median is C, the minimum is A, the maximum is E, the lower quartile (Q1) is B and the upper quartile (Q3) is D.

The value that divides the mathematical numbers or expressions in half is known as the median. The middle data point is known as the median value. Then, organize the data points in ascending order before calculating the median.

As per the given data, whiskers range from A to E.

The middle point of whisker is C.

Hence, the median is given by C.

And the whisker ranges to maximum E.

And range starts from A.

So the minimum is A.

Quartiles are three values that split sorted data into four parts, each with an equal number of observations.

The lower quartile is B and upper quartile is D.

Therefore, the answers of the median is C, the minimum is A, the maximum is E, the lower quartile (Q1) is B and the upper quartile (Q3) is D.

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