Answer:
Step-by-step explanation:
a) We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean
For the null hypothesis,
H0: µ equal to 100000
For the alternative hypothesis,
H1: µ greater than 100000
This is a right tailed test
Since the population standard deviation is nit given, the distribution is a student's t.
Since n = 200
Degrees of freedom, df = n - 1 = 200 - 1 = 199
t = (x - µ)/(s/√n)
Where
x = sample mean = 103157
µ = population mean = 100000
s = samples standard deviation = 27498
t = (103157 - 100000)/(27498/√200) = 1.62
We would determine the p value using the t test calculator.
p = 0.053
Alpha = 10% = 0.1
Since alpha, 0.1 > than the p value, 0.053, then
b) At the 10% significant level, the p-value/statistics is 0.053, so we should not reject the null hypothesis.
c) Hence, we may conclude that the average has not increased and the probability that our conclusion is correct is at least 90 percent.
