Need help with these 4 questions please! (question b)

Mathematics

1 answer:

Ainat [17]3 years ago

4 0

The answer to this question is
1. d
2.c
3.a
4.b

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You are trying to estimate the average amount a family spends on food during a year. In the past the standard deviation of the a

svetoff [14.1K]

Answer:

$n=(\frac{2.58(1000)}{50})^2 =2662.56 \approx 2663$

So the answer for this case would be n=2663 rounded up to the nearest integer

Step-by-step explanation:

We have the following info:

$ME = 50$ margin of error desired

$\sigma = 1000$ the standard deviation for this case

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =50 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 99% of confidence interval now can be founded using the normal distribution. The significance is $\alpha=0.01$ . And for this case would be $z_{\alpha/2}=2.58$ , replacing into formula (b) we got:

$n=(\frac{2.58(1000)}{50})^2 =2662.56 \approx 2663$

So the answer for this case would be n=2663 rounded up to the nearest integer

5 0

3 years ago

How would I write the equation for this table?

Rudiy27

Answer:

Step-by-step explanation:

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3 years ago

Suppose that an urn contains 3 black marbles, 7 yellow marbles, and 10 green marbles. If one marble is selected, determine the p

Yuliya22 [10]

Answer:

1/2

Step-by-step explanation:

Simple probability is a ratio of the number of ways the thing we want to happen can to the total possible outcomes.

(For example, we flip a coin and want heads, but it can land on heads or tails. Our probability of getting heads is 1/2, one way to get heads over the 2 possible outcomes)

So for this problem, there's 20 possible things that CAN happen (3 + 7 + 10) and 10 ways we get what we want (a green marble).

Our probability of getting a green marble is $\frac{10}{20\\}$ , which simplifies to $\frac{1}{2}$