Answer: 2051.64 kilowatt hours.
Step-by-step explanation:
Given : Sample size : 44
The sample mean : [tex]\overline{x}=2,000\text{ KWH. }[/tex]
Population standard deviation: [tex]s\igma= 133\text{ KWH. }[/tex]
z-value for 99% confidence interval : [tex]z_c=2.576[/tex]
The upper bound of the 99% confidence interval estimate for the population mean :-
[tex]\overline{x}+z_c\dfrac{\sigma}{\sqrt{n}}[/tex]
[tex]2000+(2.576)\dfrac{133}{\sqrt{44}}\\\\=2000+(2.576)(20.05)\\\\=2000+51.6488=2051.6488\approx2051.64[/tex]
Hence, the upper bound of the 99% confidence interval estimate for the population mean = 2051.64 kilowatt hours.
