Question

A random sample of 25 students found they spend on average $30 per week on gas with a sample standard deviation of $4. The standard error of the mean for this is: A. .73 B. 67 .C. 55 D. .44

A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics assignment  is less than 45 minutes. The correct hypothesis statement would be ___________.

A. Hₒ:µ=45; H₁:µ≥45

B. Hₒ:µ≥45; H₁:µ<45

C. Hₒ:µ=45; H₁:µ≠45

D. Hₒ:µ=45; H₁:µ>45

Answer 1

Solution :

Given that ,

standard deviation = =$4

n = 25

standard error= = / n = 4/ 25 = 0.8

(B)this is the left tailed test .  

The null and alternative hypothesis is ,

H0 :   ≥ 45

Ha : <45