A sample survey of 62 discount brokers showed that the mean price charged for a trade of 100 shares at $50 per share was $31.22. The survey is conducted annually. With the historical data available, assume a known population standard deviation of $19. (a) Using the sample data, what is the margin of error in dollars associated with a 95% confidence interval? (Round your answer to the nearest cent.) $ (b) Develop a 95% confidence interval for the mean price in dollars charged by discount brokers for a trade of 100 shares at $50 per share. (Round your answers to the nearest cent.) $ to $

a) The margin of error associated with a 95% confidence interval is of $4.73.

b) $26.49 to $35.95

Step-by-step explanation:

Question a:

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

Now, we have to find z in the Ztable as such z has a pvalue of .

So it is z with a pvalue of , so

Now, find the margin of error M as such

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

The margin of error associated with a 95% confidence interval is of $4.73.

Question b:

The lower end of the interval is the sample mean subtracted by M. So it is 31.22 - 4.73 = $26.49

The upper end of the interval is the sample mean added to M. So it is 31.22 + 4.73 = $35.95

So $26.49 to $35.95

hey there!

if she's saving for six months, let's divide the total number we need for the trip by six, dividing it into the amount that needs to be saved for each month.

500 ÷ 6 =

she needs to save at least this amount each month, so we should use this symbol: ≥

let x be the amount she saves each month.

your final answer is x ≥

hope this !

d. vertex

step-by-step explanation: