Statistics Question: For your sample complete the following: a.) A 95% one sampl
ID: 3054793 • Letter: S
Question
Statistics Question: For your sample complete the following:
a.) A 95% one sample t confidence interval for credit hours.
b.) Is there evidence at the 5% significance level that mean number of credit hours taken for all students is greater than 12 hours?
c.) Is there evidence at the 5% significance level that the mean number of credit hours taken is different than 15 hours?
Information Box: (picture wont load)
One sample T confidence interval:
u: Mean of variable
95% confidence interval results:
Variable: hours
Sample Mean: 12.96
Std. Error: 0.35188382
DF: 99
Lower Limit: 12.261786
Upper Limit: 13.658214
Sample Size:100
Explanation / Answer
a)
CI for = 95%
n = 100
mean = 12.96
t-value of 95% CI = 1.9842
std. dev. = 3.4
SE = std.dev./sqrt(n)
= 3.4/sqrt(100)
= 0.35188
ME = t*SE
= 1.9842 * 0.35188
= 0.69821
Lower Limit = Mean - ME
= 12.96 - 0.69821
= 12.26179
Upper Limit = Mean + ME
= 12.96 + 0.69821
= 13.65821
95% CI (12.2618 , 13.6582 )
b)
Hypothesis:
H0 : mu = 12
Ha : mu >12
Test statistics:
t = (x - mean)/SE
= ( 12.96 - 12)/0.35188
= 2.7282
p value = .0038
we reject the null hypothesis
There is sufficient evidence to support the claim
c)
Hypothesis:
H0 : mu = 15
Ha : mu not equal to 15
Test statistics:
t = (x - mean)/SE
= ( 12.96 - 15)/0.35188
= -5.7974
p value = .00001
we reject the null hypothesis
There is sufficient evidence to support the claim