Homework Sourse5 A car salesman claims that a particular make of car would
5) A car salesman claims that a particular make of car would give a mean mileage of greater than 20 miles/gallon. To test the claim, a field experiment was conducted where 10 cars were each run on one gallon of gas. The results (in miles) were: 23, 18, 22, 19, 19, 22, 18, 18, 24, 22. The sample standard deviation (s) = 2.32. What formula would you use to test whether the sample results support the salesman\'s claim? Use a = .05.
x - t(s ÷ n) < µ < x + t(s ÷ n)
µ = x ÷ N
z = (x - x-bar) ÷ /n
t = (x - x-bar) ÷ s/n
WHY?
| A) | x - t(s ÷ n) < µ < x + t(s ÷ n) | |
| B) | µ = x ÷ N | |
| C) | z = (x - x-bar) ÷ /n | |
| D) | t = (x - x-bar) ÷ s/n |
Solution
Option (D) is the correct formula, there is no reason, its just fact.
(A) is for CI, B is for sample mean, (c) is used when population std dev is known.
