The lnl is an absolute number which basically means it's positive regardless
So now its 7n-7=14
Simply add the 7 to the 14 to get it off the 7n side so you can simplify
Now it's 7n=21
Now just divide
21/7=3
3=N
That means 7 times N=21
The 90% , 99% confidence interval for the population mean is 32.145 <
< 35.855 and 31.093 <
< 36.907
<h3>What is Probability ?</h3>
Probability is the study of likeliness of an event to happen.
It is given that
Total Population = 50
Mean = 35
The confidence interval is given by

is the mean
z is the confidence level value
s is the standard deviation
n is the population width
(a) The 90% confidence interval for the population mean
90%
= 0.05
Z = 1.64
34
1.64 * 8 / √50
34
1.855
32.145 <
< 35.855
(b) The 99% confidence interval for the population mean
99%
= 0.005
Z=2.57
34
2.57 * 8 / √50
34
2.907
31.093 <
< 36.907
Therefore the confidence interval for population mean has been determined.
The complete question is
A simple random sample of 50 items from a population width =7 resulted in a sample mean of 35. If required, round your answers to two decimal places.
a. Provide a 90% confidence interval for the population mean
b. Provide a 99% confidence interval for the population mean
To know more about Probability
brainly.com/question/11234923
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RS+ST= RT
(7Y+3)+(2Y+9)= 14Y-8
9Y+12=14Y-8
5Y=20
Y=4