A senator wishes to estimate the proportion of United States voters who favor

abolishing the Electoral College. How large a sample is needed in order to be 90%

confident that the sample proportion will not differ from the true proportion by more

than 3%?

And rounded up we have that n=748

Step-by-step explanation:

The confidence level is 90% and the significance level would be and and the critical value for this case is:

The margin of error for the proportion interval is given by this formula:  

   (a)  

And on this case we want a margin of error of and we are interested in order to find the value of n, if we solve n from equation (a) we got:  

  (b)  

Since we don't hace any prior info for the population proportion we can use . And replacing into equation (b) the values from part a we got:

And rounded up we have that n=748

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

a

step-by-step explanation: