Question

(Extra Credit): A tax assessor wants to assess the mean property tax bill for all homeowners in East Lansing, Michigan. A past survey done a few years ago yielded a sample mean and standard deviation of 3000.00 and 1500.00 dollars respectively. How many tax records should be sampled for a margin of error of at most $200 at a confidence level of a = 0.93. O A: 162 B: 374 O C: 185 OD: 217 O E: 265

Answer 1

At alpha = 0.93

z_c = 1.81

Standard deviation = $\sigma$ = 1500

Margin of error = E = 200

We know that

$E= \frac{\sigma *z_c }{\sqrt n}$

$200= \frac{1500*1.81}{\sqrt n}$

$200= \frac{2715}{\sqrt n}$

$\sqrt n= \frac{2715}{200}$

$\sqrt n=13.575$

n = 184.28

n = 185