Known to be normally distributed with a standard deviation of $2.50. The last seven times John has taken a taxi from Logan to downtown Boston, the fares have been $22.10, $23.25, $21.35, $24.50, $21.90, $20.75, and $22.65. Construct a 95% confidence interval for the population mean.

The 95% confidence interval for the population mean is between $20.51 and $24.21.

Step-by-step explanation:

The first step to find this question is find the sample mean

Confidence interval

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 M as such

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

The lower end of the interval is the sample mean subtracted by M. So it is 22.36 - 1.85 = $20.51

The upper end of the interval is the sample mean added to M. So it is 22.36 + 1.85 = $24.21

The 95% confidence interval for the population mean is between $20.51 and $24.21.

after simplifying it i got: -36.25 as my answer. hope that !

the correct answer is you spend $55.78 more in a brand store that buy ing in a normal store.

step-by-step explanation:

brand = spend   $ 135.85 total

store = spend $80.07 total