what is the 4Th rule of probability in statistics?

Solution: The missing reason in Step 8 is substitution of [tex]x=c\cos (A)[/tex].

Explanation:

The given steps are used to prove the formula for law of cosines.

From step 5 it is noticed that our equation is

[tex]a^2=b^2-2bx+c^2[/tex]      ..... (1)

From step 7 it is noticed that the value of [tex]x[/tex] is [tex]c\cos (A)[/tex].

So by substituting [tex]c\cos (A)[/tex] for [tex]x[/tex] in equation (1) we get the equation of step 8, i.e.,

[tex]a^2=b^2-2bc\cos (A)+c^2[/tex]

Hence, the missing reason in Step 8 is substitution of [tex]x=c\cos (A)[/tex].

The missing reason in Step 8 of the proof for the Law of Cosines is substitution, where x is replaced with cc cos(A) in the expression.

The missing reason in Step 8 of the proof that shows how the Law of Cosines is derived, a2 = b2 + c2 – 2bc cos(A), is the substitution property. In Step 7, we established that c cos(A) is equal to x. Thus, for Step 8, when we replace x with cc cos(A) in the expression b2 – 2bx + c2, we effectively utilize substitution to arrive at the expression a2 = b2 – 2bccos(A) + c2.

The width of the rectangular field is 88 yards.

To find the width of the rectangular field, we can use the formula for the area of a rectangle: Area = length x width.

In this case, the area is given as 8624 yd² and the length is given as 98 yards. So, we can rearrange the formula to solve for the width: width = Area / length.

Plugging in the values, we have width = 8624 yd² / 98 yds. Dividing these values gives us the width of the field: width = 88 yards.

The triangle is a right triangle as the sides follow the Pythagorean theorem. The angles opposite the sides are 90° (largest), 53.13°, and 36.87° (smallest), listed from largest to smallest based on side lengths.

The student's question involves a triangle with sides of lengths 3 cm, 4 cm, and 5 cm and asks for the angles to be listed from smallest to largest. Since these side lengths satisfy the Pythagorean theorem (32 + 42 = 52), the triangle is a right triangle, with the right angle opposite the longest side, MO. Using the properties of a right triangle, we can determine that the smallest angle is opposite the shortest side, NM, and the next larger angle is opposite the intermediate side, NO.

To find the actual angle measurements, we would typically use trigonometric ratios such as sine, cosine, or tangent. However, since this is a 3-4-5 triangle, we already know that the angles are 90° for the right angle, and 36.87° and 53.13° for the other two angles, respectively. Thus, the angle opposite NM (3 cm) is the smallest, the angle opposite NO (4 cm) is larger, and the angle opposite MO (5 cm) is the largest, at 90 degrees.

The angle measurements in a right triangle will always follow this pattern based on the lengths of the sides, making it a straightforward matter to list them from smallest to largest.

Diagram is in the attachment below

The consecutive even integers whose squares sum to 164 are [tex]\(8\) and \(10\) or \(-10\) and \(-8\).[/tex]

Let the two consecutive even integers be  [tex]\( x \) and \( x + 2 \).[/tex]

The sum of their squares is given by:

[tex]\[ x^2 + (x + 2)^2 = 164 \][/tex]

Expanding and simplifying this equation:

[tex]\[ x^2 + (x^2 + 4x + 4) = 164 \]\[ 2x^2 + 4x + 4 = 164 \]\[ 2x^2 + 4x + 4 - 164 = 0 \]\[ 2x^2 + 4x - 160 = 0 \]\[ x^2 + 2x - 80 = 0 \][/tex]

Now, solve the quadratic equation [tex]\( x^2 + 2x - 80 = 0 \).[/tex]  We use the quadratic formula  [tex]\( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \),[/tex]  where [tex]\( a = 1 \), \( b = 2 \), and \( c = -80 \).[/tex]

[tex]\[ x = \frac{-2 \pm \sqrt{2^2 - 4 \cdot 1 \cdot (-80)}}{2 \cdot 1} \]\[ x = \frac{-2 \pm \sqrt{4 + 320}}{2} \]\[ x = \frac{-2 \pm \sqrt{324}}{2} \]\[ x = \frac{-2 \pm 18}{2} \][/tex]

This gives us two solutions:

[tex]\[ x = \frac{-2 + 18}{2} = \frac{16}{2} = 8 \]\[ x = \frac{-2 - 18}{2} = \frac{-20}{2} = -10 \][/tex]

So, the two pairs of consecutive even integers are  [tex]\( 8 \) and \( 10 \), or \( -10 \) and \( -8 \).[/tex]

Therefore, the integers are [tex]\( 8 \) and \( 10 \), or \( -10 \) and \( -8 \).[/tex]

Jude's interest rate will be 3% for the principal of $1800 on an investment.

Simple interest is defined as interest paid on the original principal and calculated with the following formula:

S.I. = P × R × T, where P = Principal, R = Rate of Interest in % per annum, and T = Time, usually calculated as the number of years. The rate of interest is in percentage r% and is to be written as r/100.

To find Jude's interest rate, we need to set up an equation using the information given. Let R be the interest rate.

The interest earned is equal to the principal times the interest rate, so the equation is:

Interest = Principal × Rate

Substituting the given values, we have:

54 = 1800 × R

Dividing both sides by 1800 gives:

R = 54 / 1800

R = 0.03, or 3%.

Therefore, for an investment of $1800, the interest rate will be 3%.

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What is the standard deviation for the data set?

212, 249, 212, 248, 239, 212, 216, 234, 248Answer:16.9

Step-by-step explanation:

To find the exact length of the curve, we can use the concept of arc length. The formula for the arc length of a curve y = f(x) on the interval [a, b] is given by: L = ∫√(1 + (f'(x))^2) dx, where f'(x) is the derivative of f(x). In this case, y2 = 4(x + 1)3 can be rewritten as y = 2√(x + 1)^3. Taking the derivative of y with respect to x, we get y' = 3(x + 1)^(3/2). Plugging this into the formula for arc length: L = ∫√(1 + (3(x + 1)^(3/2))^2) dx = ∫√(1 + 9(x + 1)^3) dx. We can then evaluate this integral over the interval [0, 1] to find the exact length of the curve.

To find the exact length of the curve y2 = 4(x + 1)3, 0 ≤ x ≤ 1, y > 0, we can use the concept of arc length. The formula for the arc length of a curve y = f(x) on the interval [a, b] is given by:

L = ∫√(1 + (f'(x))^2) dx, where f'(x) is the derivative of f(x).

In this case, y2 = 4(x + 1)3 can be rewritten as y = 2√(x + 1)^3. Taking the derivative of y with respect to x, we get y' = 3(x + 1)^(3/2). Plugging this into the formula for arc length:

L = ∫√(1 + (3(x + 1)^(3/2))^2) dx = ∫√(1 + 9(x + 1)^3) dx

We can then evaluate this integral over the interval [0, 1] to find the exact length of the curve.

Final answer:

The three consecutive odd integers whose sum is 243 are 79, 81, and 83. The integers were found using the algebraic expression for consecutive odd numbers and solving for the sum equal to 243.

Explanation:

To find three consecutive odd integers whose sum is 243, we can represent the first of these integers as 'n', the second as 'n + 2', and the third as 'n + 4', since each consecutive odd integer is 2 more than the previous one. The equation we would use to portray their sum is:

n + (n + 2) + (n + 4) = 243

Simplifying the equation, we combine like terms:

3n + 6 = 243

Next, we subtract 6 from both sides to isolate the 3n term:

3n = 243 - 6

3n = 237

Now we divide by 3 to solve for n:

n = 237 / 3

n = 79

The first odd integer is 79, the second odd integer is 79 + 2 = 81, and the third odd integer is 79 + 4 = 83.

Therefore, the three consecutive odd integers are 79, 81, and 83.

Answer:

The correct option is a.

Step-by-step explanation:

Given information: radius r =2.7 meters, arc length s = 4.32 meters.

The formula of arc length is

[tex]s=r\theta[/tex]

where, r is radius and θ is central angle in radians.

Using the above formula we get

[tex]4.32=2.7\times \theta[/tex]

Divide both sides by 2.7.

[tex]\frac{4.32}{2.7}=\theta[/tex]

[tex]1.6=\theta[/tex]

The value of the central angle is 1.6 radians. Therefore option a is correct.

Answer:

b.

21

Step-by-step explanation:

Based on the 80% figure, we'd expect 320 out of 400 adult smokers to have started before they turned 18. Observing 360 in this situation could be unusual but would require a statistical test to confirm.

This question pertains to concepts of probability and statistics. If 80% of adult smokers began smoking before they turned 18, then in a group of 400 randomly selected adult smokers, we would expect 80% (or 0.8) of that 400 to have started smoking before the age of 18. This means 320 out of the 400 individuals started smoking before turning 18.

As for the second part of the question, if we observed 360 smokers out of 400 who started smoking before turning 18, this number is higher than our expectation of 320. This could be seen as unusual, but it also might occur by chance. To determine how unusual it is, we would typically conduct a statistical test, which would require additional information not provided in the question.

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Answer:

Step-by-step explanation:33