At least 98 people need to be sampled. It is not a huge number, that is, it is not difficult to sample 98 people, so it is a reasonable sample size for a real world calculation.

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:

$\alpha = \frac{1-0.9}{2} = 0.05$

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

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$

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.

In this question:

We need a sample size of at least n.

n is found when M = 3. We have that $\sigma = 18$ .

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

$3 = 1.645*\frac{18}{\sqrt{n}}$

$3\sqrt{n} = 1.645*18$

Simplifying by 3

$\sqrt{n} = 1.645*6$

$(\sqrt{n})^{2} = (1.645*6)^{2}$

$n = 97.41$

Rounding up,

At least 98 people need to be sampled. It is not a huge number, that is, it is not difficult to sample 98 people, so it is a reasonable sample size for a real world calculation.

8 0

3 years ago

Using the results from the table, predict the number of times a 3 would be rolled in 400 trials.

sasho [114]

First you should add all the number of rolls.
The number of rolls is 80.
Subtract 80 from 400.
The answer is 320.
Add 320 to the number of rolls of 3.
The answer to the question is 322.
I am sorry if I am wrong.

5 0

3 years ago

Read 2 more answers

Whats 1/2 ÷ 2/3 and i need it simplyified if needed

MariettaO [177]

Answer:3/4

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Whats greater 9.354 or 9.012

babymother [125]