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3 years ago

I need help with this please

Mathematics

1 answer:

KatRina [158]3 years ago

5 0

Answer: a) 12

Step-by-step explanation: anything with parentheses means times (×)

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Mr. snorkel drove 169 miles in 3 h 30 min. find the rate in feet per second.

mars1129 [50]

Simple...

3 hours 30 min--->>>3.5

$\frac{169}{3.5}=48$ (rounded)

Thus, your answer.

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3 years ago

What are two square numbers added together equal 65?

pychu [463]

8 and 1
8 squared is 64 and 1 squared is 1
64 + 1 = 65
Hope this helps :)

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3 years ago

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3 years ago

Which point can be found using the vertical line x = –9 and the horizontal line y = 8? A. (–8,9) B. (8,–9) C. (–9,8) D. (9,–8)

bezimeni [28]

C because that is the point at which x is -9 and y is 8

7 0

3 years ago

In order to set rates, an insurance company is trying to estimate the number of sick days that full time workers at an auto rep

son4ous [18]

Answer:

D. 31

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.95}{2} = 0.025$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.025 = 0.975$ , so Z = 1.96.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

A previous study indicated that the population standard deviation is 2.8 days.

This means that $\sigma = 2.8$

How large a sample must be selected if the company wants to be 95% confident that the true mean differs from the sample mean by no more than 1 day?

This is n for which M = 1. So

$M = z\frac{\sigma}{\sqrt{n}}$

$1 = 1.96\frac{2.8}{\sqrt{n}}$

$\sqrt{n} = 1.96*2.8$

$(\sqrt{n})^2 = (1.96*2.8)^2$

$n = 30.12$

Rounding up, at least 31 people are needed, and the correct answer is given by option D.

5 0

3 years ago