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2 years ago

I need the answer to these parts. The last is correct or incorrect

Mathematics

1 answer:

Margaret [11]2 years ago

6 0

Answer:

Step-by-step explanation:

40% of the regular price

subtracting it from

10% off each

(not sure of the last one)

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A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained p

Alekssandra [29.7K]

Using the z-distribution and the formula for the margin of error, it is found that:

a) A sample size of 54 is needed.

b) A sample size of 752 is needed.

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which z is the z-score that has a p-value of $\frac{1+\alpha}{2}$ .

The margin of error is of:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

90% confidence level, hence $\alpha = 0.9$ , z is the value of Z that has a p-value of $\frac{1+0.9}{2} = 0.95$ , so $z = 1.645$ .

Item a:

The estimate is $\pi = 0.213 - 0.195 = 0.018$ .

The sample size is <u>n for which M = 0.03</u>, hence:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.03 = 1.645\sqrt{\frac{0.018(0.982)}{n}}$

$0.03\sqrt{n} = 1.645\sqrt{0.018(0.982)}$

$\sqrt{n} = \frac{1.645\sqrt{0.018(0.982)}}{0.03}$

$(\sqrt{n})^2 = \left(\frac{1.645\sqrt{0.018(0.982)}}{0.03}\right)^2$

$n = 53.1$

Rounding up, a sample size of 54 is needed.

Item b:

No prior estimate, hence $\pi = 0.05$

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.03 = 1.645\sqrt{\frac{0.5(0.5)}{n}}$

$0.03\sqrt{n} = 1.645\sqrt{0.5(0.5)}$

$\sqrt{n} = \frac{1.645\sqrt{0.5(0.5)}}{0.03}$

$(\sqrt{n})^2 = \left(\frac{1.645\sqrt{0.5(0.5)}}{0.03}\right)^2$

$n = 751.7$

Rounding up, a sample of 752 should be taken.

A similar problem is given at brainly.com/question/25694087

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2 years ago

Loni’s credit card statement for April showed a membership fee of $85, a late fee of $45, a finance charge of $7.45, and an over

Jlenok [28]

Answer:

$157.45

Step-by-step explanation:

All the amounts provided in the question are supposed to be added as a fee, so if you add all the numbers you would get $157.45.

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3 years ago

Are the co ordinates of A 3,4 ?

Lubov Fominskaja [6]

Answer:

A: 2,3

B: -5,1

for ii and iii and b), the easiest way to find the points are by moving on the x-axis(straight across/ horizontal line), then the y-axis(the up to down one). the first point for example (-3,-2), you would move 3 times to the left, and 2 times to the bottom, because if its a negative x, you move left, while if its a positive x, you move right, and if its a negative y, you move down, while a positive y moves you up.

Step-by-step explanation:

I really hope it helps!!!

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2 years ago

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Simplify the following expression! Please

Alex Ar [27]

2(-20)+3[5/4(-20)]

-40 + 3[-25]
-40 + -75
-115

-115 is your final answer.

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3 years ago

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On a piece of paper, graph y+2>-3x-3.