Answer:
Sample size should be atleast 60025
Step-by-step explanation:
Given that a school board wishes to know the current mean reading level of 6th graders throughout a very large school district. Past experience shows that the standard deviation of such reading scores is about 2.5
For 95% confidence we have significance level = 5%
Margin of error = 0.04
Margin of error should be less than 0.04
i.e. Z critical value for 95% *std error <0.04
[tex]1.96*\frac{2.5}{\sqrt{n} } <0.02\\\\n>60025[/tex]
Sample size should be atleast 60025
