Complete question :
Past experience indicates that the time required for high school seniors to complete a standardized test is a normal random variable with a mean of 35 minutes. If a random sample of 20 high school seniors took an average of 33.1 minutes to complete this test with a standard deviation of 4.3 minutes, test the hypothesis, at the 0.05 level of significance.
Answer:
We conclude they there is significant evidence to support the claim That time required for high school seniors to complete test is less than 35 minutes.
Step-by-step explanation:
H0 : μ = 35
H1 : μ < 35
Sample size, n = 20
Standard deviation, s = 4.3
xbar = 33.1
Test statistic :
T = (xbar - μ) ÷ (s /√n)
T = (33.1 - 35) ÷ (4.3 /√20)
T = - 1.9 ÷ 0.9615092
T = - 1.976
The Pvalue can be obtained from the test statistic using a Pvalue calculator :
Pvalue at 0.05 ; df = 19 is 0.0314
Since, Pvalue < α ; We reject the Null and conclude that time required for high school candidate to complete test is less than 35 minutes
