Answer:
The 90% confidence interval for the mean combined fuel economy for Ford Explorers is between 22.95 and 23.63 mpg.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 16 - 1 = 15
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 15 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.7531
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 23.29 - 0.34 = 22.95 mpg
The upper end of the interval is the sample mean added to M. So it is 23.29 + 0.34 = 23.63 mpg
The 90% confidence interval for the mean combined fuel economy for Ford Explorers is between 22.95 and 23.63 mpg.
I dont see a question that i can anwser i need more information
Answer:
6 5/12
Step-by-step explanation:
2 2/3 as a mixed number is 8/3
3 3/4 as a mixed number is 15/4
To make the 2 fractions have a common denominator, they become:
32/12 and 45/12
to add them up it will be: 77/12 which can be written as 6 5/12
Answer:
C
Step-by-step explanation:
-4+(-5)=-9
-4=-9+5
-4=-4......correct
Well 85% of 25 is 21.25. So the closest ones would be 20 or 22. Well let's check out the difference's. 21.25-20= 1.25.....22-21.25=.75. well clearly .75 is smaller than 1.25 so your answer would be 22. 85% of 25 is closest to 22.