Question

Find or graph the following: a) point estimate b) distribution used c) 95% Confidence Interval d) Margin of Error d) graph e) Write in words (in reference to your problem) the meaning of the confidence interval.

3) From previous studies, it was determined that the amount of soda contained in a can for a certain brand had a standard deviation of 0.1 ounces. A random sample of 40 cans of soda was selected and the amount of soda in each can was measured. From the sample gave a mean of 12.03 ounces and standard deviation of 0.08 ounces.  

Answer 1

3)

Given information:

a)

The point estimate for population mean is sample mean. So required point estimate is .

b)

Since sample size is greater than 30 so we can apply CLT.

That is normal distribution can be used.

c)

For 95% confidence interval, using excel function "=NORMSINV(0.975)", critical value of z is . So required confidence interval is

Therefore, a 95% confidence interval is (11.999, 12.061).

d)

The margin of error is:

e)

Following is the graph:

e)

It shows that we are 95% confident that true amount of soda contained in a can is lies in the above interval.