Question

a) If n=10, ¯xx¯(x-bar)=33, and s=10, construct a confidence interval at a 80% confidence level. Assume...

a) If n=10, ¯xx¯(x-bar)=33, and s=10, construct a confidence interval at a 80% confidence level. Assume the data came from a normally distributed population.

Give your answers to one decimal place.

< μμ <

b) In a survey, 27 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $46 and standard deviation of $8. Find the margin of error at a 99% confidence level.

Give your answer to two decimal places.

c) If n=29, ¯xx¯(x-bar)=36, and s=8, find the margin of error at a 90% confidence level

Give your answer to two decimal places.

Homework Answers

Answer #1

a)

80% Confidence Interval
X̅ ± t(α/2, n-1) S/√(n)
t(α/2, n-1) = t(0.2 /2, 10- 1 ) = 1.383
33 ± t(0.2/2, 10 -1) * 10/√(10)
Lower Limit = 33 - t(0.2/2, 10 -1) 10/√(10)
Lower Limit = 28.6
Upper Limit = 33 + t(0.2/2, 10 -1) 10/√(10)
Upper Limit = 37.4

28.6 < < 37.4

b)

t critical value at 0.01 significance level with 26 df = 2.779

Margin of error = t * S / sqrt(n)

= 2.779 * 8 / sqrt(27)

= 4.28

c)

t critical value at 0.1 significance level with 28 df = 1.701

Margin of error = t * S / sqrt(n)

= 1.701 * 8 / sqrt(29)

= 2.53

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
Similar Questions
1. If n=19, ¯xx¯(x-bar)=34, and s=12, construct a confidence interval at a 95% confidence level. Assume...
1. If n=19, ¯xx¯(x-bar)=34, and s=12, construct a confidence interval at a 95% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. 2. In a survey, 11 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $50 and standard deviation of $15. Construct a confidence interval at a 90% confidence level. Give your answers to one decimal place....
1) If n=19, ¯xx¯(x-bar)=33, and s=18, construct a confidence interval at a 80% confidence level. Assume...
1) If n=19, ¯xx¯(x-bar)=33, and s=18, construct a confidence interval at a 80% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. < μμ < 2) You measure 48 backpacks' weights, and find they have a mean weight of 44 ounces. Assume the population standard deviation is 2.8 ounces. Based on this, construct a 95% confidence interval for the true population mean backpack weight. Give your answers as decimals, to two...
If n=21, ¯xx¯(x-bar)=44, and s=17, construct a confidence interval at a 98% confidence level. Assume the...
If n=21, ¯xx¯(x-bar)=44, and s=17, construct a confidence interval at a 98% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. < μμ <
If n=32, ¯xx¯(x-bar)=36, and s=5, construct a confidence interval at a 90% confidence level. Assume the...
If n=32, ¯xx¯(x-bar)=36, and s=5, construct a confidence interval at a 90% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. < μμ <
If n=15, ¯xx¯(x-bar)=33, and s=10, construct a confidence interval at a 98% confidence level. Assume the...
If n=15, ¯xx¯(x-bar)=33, and s=10, construct a confidence interval at a 98% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.
If n=28, ¯xx(x-bar)=46, and s=7, find the margin of error at a 95% confidence level Give...
If n=28, ¯xx(x-bar)=46, and s=7, find the margin of error at a 95% confidence level Give your answer to two decimal places.
If n=30, ¯xx¯(x-bar)=49, and s=10, construct a confidence interval at a 90% confidence level. Assume the...
If n=30, ¯xx¯(x-bar)=49, and s=10, construct a confidence interval at a 90% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. _______< ? < ________
QUESTION PART A: In a survey, 29 people were asked how much they spent on their...
QUESTION PART A: In a survey, 29 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $35 and standard deviation of $4. Find the margin of error at a 98% confidence level. Give your answer to two decimal places. QUESTION PART B: If n=12, ¯xx¯(x-bar)=44, and s=11, construct a confidence interval at a 95% confidence level. Assume the data came from a normally distributed population. Give your...
If n=18, ¯xx¯(x-bar)=40, and s=10, find the margin of error at a 99% confidence level Give...
If n=18, ¯xx¯(x-bar)=40, and s=10, find the margin of error at a 99% confidence level Give your answer to two decimal places.
If n=13, (x-bar)=34, and s=4, construct a confidence interval at a 90% confidence level. Assume the...
If n=13, (x-bar)=34, and s=4, construct a confidence interval at a 90% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. ____ < μμ < ____
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT