Question

# 1) The average annual salary based on a sample of 36 school administrators is \$58,940, with...

1) The average annual salary based on a sample of 36 school administrators is \$58,940, with a standard deviation of \$18,490. (Please label your ans. a, b, c etc) a) Find the 95% confidence interval for the population mean annual salary of school administrators. b) What is the Margin of Error from part a? c) If the sample size is increased to 100, will the margin of error increase or decrease in part a?

#### Homework Answers

Answer #1

1)

t critical value at 0.05 level with 35 df = 2.030

95% confidence interval for is

- t * S / sqrt(n) < < + t * S / sqrt(n)

58940 - 2.030 * 18490 / sqrt( 36) < < 58940 + 2.030 * 18490 / sqrt( 36)

52684.22 < < 65195.78

95% CI is ( 52684.22 , 65195.78 )

2)

Margin of error =  t * S / sqrt(n)

=  2.030 * 18490 / sqrt( 36)

= 6255.78

3)

If sample size increased to 100 , margin of error decreases. (since quantity S/sqrt(n) will reduce)

Know the answer?
Your Answer:

#### Post as a guest

Your Name:

What's your source?

#### Earn Coins

Coins can be redeemed for fabulous gifts.

##### Not the answer you're looking for?
Ask your own homework help question
ADVERTISEMENT
##### Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

ADVERTISEMENT