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Helpful source:
https://percent-calc.com/what-is-9-of-15000
Answer:
a)
b) 
c) Since the p value is higher than the significance level provided we have enogh evidence to FAIL to reject the null hypothesis and we can't conclude that the true means are different at 5% of significance
Step-by-step explanation:
Information given
represent the mean for 1
represent the mean for 2
represent the population standard deviation for 1
represent the population standard deviation for 2
sample size for the group 1
sample size for the group 2
z would represent the statistic
Hypothesis to test
We want to check if the two means for this case are equal or not, the system of hypothesis would be:
H0:
H1:
The statistic would be given by:
(1)
Part a
Replacing we got:

Part b
The p value would be given by this probability:

Part c
Since the p value is higher than the significance level provided we have enogh evidence to FAIL to reject the null hypothesis and we can't conclude that the true means are different at 5% of significance
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