1/4 + 1/8 + 3/8 = (2*1 +1 +3)/8 = (2+1+3)/8 = 6/8 = 3/4
hope helped
Answer:
The margin of error of u is of 3.8.
The 99% confidence interval for the population mean u is between 27.4 minutes and 35 minutes.
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 = 28 - 1 = 27
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 27 degrees of freedom(y-axis) and a confidence level of
. So we have T = 2.7707
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The margin of error of u is of 3.8.
The lower end of the interval is the sample mean subtracted by M. So it is 31.2 - 3.8 = 27.4 minutes
The upper end of the interval is the sample mean added to M. So it is 31.2 + 3.8 = 35 minutes
The 99% confidence interval for the population mean u is between 27.4 minutes and 35 minutes.
Answer:
oh my god
Step-by-step explanation:
why is your image blockedddd
Answer:
c^3 + c^2 - 7c + 20
Step-by-step explanation:
First, expand the expression using distributive property.
c^2(c+4) - 3c(c+4) + 5(c+4)
c^3 + 4c^2 - 3c^2 - 12c + 5c + 20
Lastly, simplify like terms.
c^3 + c^2 - 7c + 20
X=8.
Following the similarity statement, we know that AC is to DF as BC is to EF. The ratio would be:
24/(x-2) = 20/5
Cross multiply:
24*5 = 20(x-2)
Use the distributive property:
120 = 20x - 40
Add 40 to both sides:
120+40 = 20x - 40 + 40
160 = 20x
Divide both sides by 20:
160/20 = 20x/20
8 = x