Question

the average number of mosquitos caught in 64 mosquito traps in a particular environment was 700 per trap . the standard deviation of mosquitos caught in the entire population of traps is 100 mosquitos. what is the 99% condidence interval for the true mena number of mosquitos caught in all mosquito traps

Answer 1

the 99% confidence interval for the true mean number of mosquitos caught in all mosquito traps is ( 667.81, 732.19 )

Explanation:

Given the data in the question;

sample mean x' = 700

sample size n = 64

the standard deviation σ = 100

99% confidence interval for the true mean number of mosquitos caught in all mosquito traps = ?

significance level ∝ = 1 - 99% = 1 - 0.99 = 0.01

∝/2 = 0.01 / 2 = 0.005

Z-critical
`Z_{\alpha /2` = 2.575 { from table }

So, to get the 99% confidence interval;

⇒ x' ±
`Z_{\alpha /2` ( σ / √n )

we substitute

⇒ 700 ± 2.575 ( 100 / √64)

⇒ 700 ± 2.575( 12.5 )

⇒ 700 ± 32.1875

⇒ ( 700 - 32.1875 ), ( 700 + 32.1875 )

⇒ ( 667.81, 732.19 )

Therefore, the 99% confidence interval for the true mean number of mosquitos caught in all mosquito traps is ( 667.81, 732.19 )