Question

Your firm wants to investigate how much money the typical tourist will spend on their next visit to New York. How many tourists should be included in your sample if you want to be 90% confident that the sample mean is within $17 from the population mean? From previous studies, we know that the standard deviation is $70.

Answer 1

46

Explanation:

Your firm wants to investigate how much money the typical tourist will spend on their next visit to New York. Therefore, 46 tourists should be included in your sample if you want to be 90% confident that the sample mean is within $17 from the population mean. From previous studies, we know that the standard deviation is $70.

Answer 2

Answer: 46

Explanation:

Given : Margin of error : E= 17

Standard deviation :
`\sigma=70`

Critical value for 90% confidence level :
`z_(\alpha/2)=1.645`

Formula to find sample size is given by :-

`n=((z_(\alpha/2)* \sigma)/(E))^2`

i.e.
`n=(((1.645)* 70)/(17))^2`

`\Rightarrow\ n=45.880700692\approx46`

Hence, the required minimum sample size = 46.