Statistics

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Question3.xlsx

Sheet1

A theme park owner wants to know if the children’s rides are favoring 10 year old girls over 10 year old boys based on height. In other words, does one group taller than the other and thus can go on more rides? (Note: amusement parks determine whether someone can go on a ride based on height.)
Part a: The owner gathered height data on 10 year old girls and 10 year old boys, see excel document for data. Determine at the 5% significance level if there is evidence that the two genders are not the same height and thus cannot all go on the same rides. Show your work and give your answer in complete sentences in context of the problem.
Part b: After doing some research, the owner found the following information about the expected height and standard deviation for 10 year olds. Does that change the result of part a? Show your work and give your answer in complete sentences in context of the problem.
10 year old girls 10 year old boys
Average height 54.5 inches 54.5 inches
St. deviation 2.74 inches 2.71 inches
10 year old girls 10 year old boys Overall Ho: (girls - boys) = 0 F-Test Two-Sample for Variances
52.3 58.1 Ha: (girls - boys) not = 0
53.5 53.0 10 year old girls 10 year old boys
53.6 56.2 alpha = 0.05 Mean 54.4045454545 54.3611111111
53.0 54.2 First Test: check variances Variance 6.8671212121 7.9966339869
56.9 50.9 Observations 22 18
51.2 54.4 Ho: variances are the same df 21 17
48.6 51.4 Ha: variance are different F 0.8587514726
51.3 53.5 pvalue 0.7318071586 P(F<=f) one-tail 0.3659035793
53.9 51.0 pvalue > alpha F Critical one-tail 0.4675360873
54.0 59.7
57.5 53.4 do not reject
53.7 49.2
55.7 55.7 Assume variance are the same
54.9 55.1
57.9 57.7
56.9 57.7
59.9 52.6 Second Test: t-test to check the data hypothesis (girls vs boys) t-Test: Two-Sample Assuming Equal Variances
56.6 54.7
54.6 pvalue 0.9601213383 10 year old girls 10 year old boys
52.9 pvalue > alpha Mean 54.4045454545 54.3611111111
52.0 Do not reject the null hypothesis Variance 6.8671212121 7.9966339869
56.0 Observations 22 18
The data suggests there is no difference in the height between girls and boys. Pooled Variance 7.3724295587
Therefore they can all go on the same rides. Hypothesized Mean Difference 0
df 38
t Stat 0.050332157
P(T<=t) one-tail 0.4800606691
t Critical one-tail 1.6859544602
P(T<=t) two-tail 0.9601213383
t Critical two-tail 2.0243941639