Question 3 1B pf: To determine whether a driver\'s education course improves the
ID: 3054423 • Letter: Q
Question
Question 3 1B pf: To determine whether a driver's education course improves the scores on a driving exam, a sample of 6 students were given the exam before and after taking the course. The results are shown below Score Score Student Before the Course After the Course 87 83 89 93 2 91 4 93 83 86 79 a) Does the course improve the score on the driving exam? Usea0.05 b) State and check the assumptions for the above test. c) Give a 95% confidence interval for the gain in exam score after taking the courseExplanation / Answer
a)
Null Hypothesis : H0: ?1 - ?2 >= 0
Alternate Hypothesis: Ha: ?1 - ?2 < 0
dbar = ?(before) - ?(after) = -2
s(dbar) = 3.5214
SE = s(dbar)/sqrt(n) = 1.4376
Test Statisitcs, t = dbar/SE = -1.3912
degrees of freedom = n-1 = 5
p-value = 0.1114
As p-value is greater than the significance level of 0.05, we fail to reject the null hypothesis.
There are not significant evidence to conclude that exam improves the scores.
b)
Assumptions are
1. The difference of the test scores are normally distributed.
2. sample is randomly selected
c)
x1bar - x2bar = -2.00
SE = 1.4376
CI = 95%
DF = 5
t-value = 2.5706
ME = t*SE = 3.6954
Confidence Interval is (x1bar - x2bar) +/- ME
Lower bound = -5.69544
Upper bound = 1.69544
Confidence Interval is (-5.6954 , 1.6954 )
Before After dbar 83 87 -4 89 88 1 93 91 2 77 77 0 86 93 -7 79 83 -4 Mean -2Related Questions
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