A 98% confidence interval for the mean of a population is to be constructed and must be accurate to within 0.3 unit. A preliminary sample standard deviation is 1.7. The smallest sample size n that provides the desired accuracy is

And the value for n rounded up would be n = 174

Step-by-step explanation:

We have the following info given:

previous estimation for the deviation

the margin of error desired

represent the confidence

The Margin of error is given by:

If we solve for the value of n we got:

For this problem we know that the confidence is 98% so then the significance level would be and the critical value would be:

And replacing we got:

And the value for n rounded up would be n = 174

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.

$30.32

step-by-step explanation:

65.00*.12=2.80

65.00-2.80=57.20

57.20*1.06=60.632

60.632/2=30.316