0.068 rounded to the nearest thousandth
I think that D is the answer
The correct answer is option D.
Answer:
There is significant evidence to conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.
Step-by-step explanation:
Given the data :
6.2 7.1 5.4 5.5 7.5 2.6 4.3 2.9 3.7 0.7 5.6 1.7
The hypothesis:
H0: μ = 3.2
H1 : μ > 3.2
n = sample size = 12
The sample mean, xbar = ΣX / n
xbar = 53.2 / 12
xbar = 4.43
Using calculator;
Sample standard deviation, s = 2.147
The test statistic :
(xbar - μ) ÷ (s/sqrt(n))
(4.43 - 3.2) ÷ (2.147/sqrt(12)
1.23 / 0.6197855
Test statistic = 1.985
The Pvalue using the Pvalue from Tscore calculator :
Tscore = 1.985 ; df = 12 - 1 = 11
Pvalue = 0.036
Since Pvalue < α ; We reject the Null
Hence, we conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.
