Alot! So the ones with 5 like 15,25,35,45,55,65,75,85,95! Each one inbetween is 10 so it would be 80
Answer:
The 90% confidence interval is 
Step-by-step explanation:
From the question we are told that
The sample size is n = 64
The sample mean is 
The standard deviation is 
Given that the confidence interval is 90% then the level of significance is mathematically evaluated as


Next we obtain the critical value of
from the normal distribution table , the value is

Generally the margin of error is mathematically represented as

=> 
=> 
The 90% confidence interval is mathematically represented as

=> 
=> 
x=7-2t
Move 7 to the other side. Sign changes from +7 to -7.
x-7=7-7-2t
x-7=-2t
Divide by -2 for both sides
x/-2-7/-2=-2t/-2
x/2+7/2=t
Answer: t= x/2+7/2 or t=7/2+x/2
Answer:
13.96
Step-by-step explanation:
Standard deviation is the square root of the variance, so it's

≈ 13.96