Answer:
Step-by-step explanation:
Given that
Population mean 
std deviation
= 12
sample size n =36
Sample mean = 

(Two tailed test)
Mean difference = 7
Std error =
Since population std dev is known and n>30 we use Z test
Z statistic = 
p value <0.001
Since p value is <0.01, at 1% significance level, we reject H0.
There is significant difference between sample mean and population mean.
Answer:
Erin ran 12.5 miles
Luis ran 7.5
In all they ran 20 miles.
Step-by-step explanation:
Erin: 5 x 3.5 = ?
Luis: 3 x 2.5 = ?
----------------------------
5 x 2.5 = 12.5 . Erin ran 12.5 miles
3 x 2.5 = 7.5 . Luis ran 7.5 miles
7.5 + 12.5 = 20 miles
They ran 20 miles all together.
Hope this helps!
That would be 8000.. hope it helps
Answer:
y-intercept is (0, 1)
Step-by-step explanation: