Question

1. The real estate broker claims that “on average, 70 people passes by the store every hour.” A sample of 12 hours revealed the following number of people passes by.

64, 66, 64, 66, 59, 62, 67, 61, 64, 58, 54, 66

1. 1. What is the point estimate of the population mean, i.e. sample mean?
2. 2. What is the sample standard deviation? (I didn’t show you how to do this using your calculator this year, therefore, I am giving you the answer here; however, in the exam, it is expected you know how to compute it using your own calculator.)
3. 3. Develop a 90% confidence interval for the population mean.
4. 4. Develop a 95% confidence interval for the population mean.
5. 5. Comment on the validity of the claim made by real estate broker.

I think this claim is (Valid / Invalid).             Reasons:

Answer 1

a) Since we know that

b) Since we know that

c)

Confidence interval(in %) = 90

Required confidence interval = (62.58-2.0436, 62.58+2.0436)

Required confidence interval = (60.5364, 64.6236)

d)

Confidence interval(in %) = 95t = 2.20

Required confidence interval = (62.58-2.5034, 62.58+2.5034)

Required confidence interval = (60.0766, 65.0834)

Please hit thumps up if the answer helped you.

e)

Invalid as all the value are below 70 and 70 is not in any confidence interval