Answer:
(1589.55,1791.45)
Step-by-step explanation:
Given that, population standard deviation = 325 words
sample size ( n ) = 25 and sample mean = 1640 words
A 98% confidence level has significance level of 0.02 and critical value is, Z* = 2.33
The 98% confidence interval for population mean is,
[tex]1640- 2.33\times\frac{325}{\sqrt{25} } <\mu<1640+2.33\times\frac{325}{\sqrt{25} }[/tex]
1640-151.45<μ<1640+151.45
1589.55<μ<1791.45
therefore the confidence interval is (1589.55,1791.45)
