Answer:
There isn't sufficient evidence that support the claim that mean cost differs from $117.91
Step-by-step explanation:
Given that :
Population Mean cost, μ = 117.91
Sample size, n = 36
Sample mean, xbar = 122.57
Sample standard deviation, s = 20
The hypothesis :
H0 : μ = 117.91
H0 : μ ≠ 117.91
Using the one sample t test :
Test statistic
(xbar - μ) ÷ s/sqrt(n)
T = (122.57 - 117.91) ÷ 20/sqrt(36)
T = 4.66 / 3.333
T = 1.398
Decision region :
Reject H0 ; If Pvalue < α
α = 0.10
Degree of freedom, df = n - 1 = 36 - 1 = 35
Pvalue(1.398, 35) = 0.1709
Since 0.1709 > 0.10 ; WE fail to reject H0 ; therefore there isn't sufficient evidence that support the claim that mean cost differs from $117.91