A sample of 50 provided a sample mean of 19.4. The population standard deviation
ID: 3063375 • Letter: A
Question
A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2.
a. Compute the value of the test statistic. Round your answer to two decimal places.
b. What is the p-value? Round your answer to four decimal places.
c. Using = .05, what is your conclusion?
The input in the box below will not be graded, but may be reviewed and considered by your instructor.
d. What is the rejection rule using the critical value? What is your conclusion?
The input in the box below will not be graded, but may be reviewed and considered by your instructor.
Explanation / Answer
Ans:
a)Test statistic:
z=(19.4-20)/(2/sqrt(50))=-2.12
b)
p-value(left tailed)=P(z<-2.12)=0.0169
c)As,p-value<0.05,we reject null hypothesis.
There is enough evidence to conclude that population mean is less than 20.
d)critical z value=-1.645
As,z=-2.12<-1.645,we reject null hypothesis.
There is enough evidence to conclude that population mean is less than 20.