the mean of a sample size n=35 is 1860. the standard deviation of the sample is 102 and the population is normally distributed. construct a 99% confidence interval estimate of the mean of the population.

Respuesta :

Answer: (1812.967, 1907.033)

Step-by-step explanation:

The confidence interval for population mean is given by :-

[tex]\overline{x}\pm t_{df,\ \alpha} \dfrac{s}{\sqrt{n}}[/tex]

, where [tex]\overline{x}[/tex] = Sample mean

n= Sample size.

s = Sample standard deviation

[tex]t_{df,\ \alpha}[/tex] = Critical t-value for degree of freedom(n-1).

As per given , we have

n= 35

[tex]\overline{x}=1860[/tex]

s=102

Significance level : [tex]\alpha=0.01[/tex]

By t- distribution table , for degree of freedom 43 and [tex]\alpha=0.01[/tex] , we have

[tex]t_{df,\ \alpha}=t_{34,\ 0.005} =2.728[/tex]

Substitute all the values in the above formula , we will get

[tex]1860\pm (2.728)\dfrac{102}{\sqrt{35}}[/tex]

[tex]=1860\pm (2.728)(17.2411)[/tex]

[tex]=1860\pm47.034[/tex]

[tex]=(1860-47.033\ 1860+47.033)= (1812.967,\ 1907.033)[/tex]

Hence, the  99% confidence interval estimate of the mean of the population is  (1812.967, 1907.033).