<h2>
Answer with explanation:</h2>
Let
be the population mean lifetime of circulated $1 bills.
By considering the given information , we have :-

Since the alternative hypotheses is two tailed so the test is a two tailed test.
We assume that the lifetime of circulated $1 bills is normally distributed.
Given : Sample size : n=50 , which is greater than 30 .
It means the sample is large so we use z-test.
Sample mean : 
Standard deviation : 
Test statistic for population mean :-


The p-value= 
Since the p-value (0.0433834) is greater than the significance level (0.02) , so we do not reject the null hypothesis.
Hence, we conclude that we do not have enough evidence to support the alternative hypothesis that the average lifetime of a circulated $1 bill differs from 18 months.
Answer:
What is the question tho?
Step-by-step explanation:
Answer:
y=2
Step-by-step explanation:
1/3 (y+7) = 3(y-1)
Multiply each side by 3 to get rid of the fraction
3*1/3 (y+7) = 3*3(y-1)
y+7 = 9(y-1)
Distribute
y+7 = 9y - 9
Subtract y from each side
y+7-y = 9y-y-9
7 = 8y -9
Add 9 to each side
7+9 = 8y-9+9
16 = 8y
Divide each side by8
16/8 = 8y/8
2 = y