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.
You divide 125.6 by 3.14 which = 68.66
That's the diameter. so the nearest cm is 69cm
The radius is half of the diameter so to the nearest cm it is 34cm
Answer:
the slope is -2/5
Step-by-step explanation:
you do y2-y1 on top of the division sign and x2-x1 on the bottom.
Is there a piece of paper that comes with the questions? Or do I just pick one? If there is a piece of paper attached, please add it to your question. Thank you!
Answer:
length = 78 m , width = 27 m
Step-by-step explanation:
let w represent width then length l = 3w - 3
the perimeter (P) is calculated as
P = 2l + 2w = 210 , substitute values
2(3w - 3) + 2w = 210 ← distribute parenthesis and simplify left side
6w - 6 + 2w = 210
8w - 6 = 210 ( add 6 to both sides )
8w = 216 ( divide both sides by 8 )
w = 27 and l = 3(27) - 3 = 81 - 3 = 78
Then length = 78 m and width = 27 m