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.
No, becasue of PEMDAS
so parenthasees first
exponents next
mulitplciation next
(-2)^4=-2 times -2 times -2 times -2=positive number since even number of negative signs
-2^4=-1 times 2^2=-1 times 2 times 2 times 2 times 2=negative number since odd number of negative signs
1. Answer x=-5
You would subtract 25 from each side of the equal sign, taking 25 away from 40 and 25 away from 25, isolating the x. So you would then have -3x=15. You would then divide each side by -3, and getting x=-5