Respuesta :
Answer:
[tex]68.04-1.959\frac{35.74}{\sqrt{250}}=63.618[/tex]
[tex]68.04+1.959\frac{35.74}{\sqrt{250}}=72.461[/tex]
And the best option for this case would be
Step-by-step explanation:
Information given
[tex]\bar X=68.04[/tex] represent the sample mean
[tex]\mu[/tex] population mean
s=35.74 represent the sample standard deviation
n=250 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex] (1)
The degrees of freedom are given by:
[tex]df=n-1=250-1=249[/tex]
The Confidence level is 0.95 or 95%, and the significance [tex]\alpha=0.05[/tex] and [tex]\alpha/2 =0.025[/tex], and the critical value for this case woud be [tex]t_{\alpha/2}=1.956[/tex]
And replacing we got:
[tex]68.04-1.959\frac{35.74}{\sqrt{250}}=63.618[/tex]
[tex]68.04+1.959\frac{35.74}{\sqrt{250}}=72.461[/tex]
And the best option for this case would be