Assuming that the average IQ score for all people is 100 with a standard deviati
ID: 3224552 • Letter: A
Question
Assuming that the average IQ score for all people is 100 with a standard deviation of 15, Dr. Sheldon belives that students enrolled in his statistics course are significantly less intelligent than the population as a whole. He has discovered that the mean IQ of the 17 students who enrolled in his safety 341 class this semester was 102.7 Use a=.05 1. State the null and alternate hypotheses in both word form and equation form. 2. Select the appropriate test statistic to use. 3. State the decision rule. 4. Calulate the test staistic 5. State the conclusion concerning the nul hypothesis. 6. Interpret the results of Dr. Sheldon;s Experiment. Based on this experiment, can Dr. Sheldon support his claim.
Explanation / Answer
Hypothesis:
H0 : mu = 102.7
Ha; mu < 102.7
2)
we use t as the test statistic.
t = ( x - mean) / ( s/sqrt(n))
3)
Reject Ho if the z value falls in the rejection region. Fail to reject H0 if it falls in the nonrejection region.
With alpha = .05 and the inequality we have the entire rejection region at the left. The critical value will be t = -1.746. Reject H0 if t < -1.746.
4)
Test statistic;
x = 100 , s = 15 , n = 17
t = ( x - mean) / (s / sqrt(n))
= (100 - 102.7) / ( 15/sqrt(17))
= -0.74
P value is calculated using t = -0.74 , df = 16
p value =.23501.
5) We fail to reject H0
6)
Dr. Sheldon Based on this experiment, cannot Dr. Sheldon support his claim.