Prices of diamonds are very sensitive to their weight (measured in carat). For example, the price of a 1 carat diamond tends to be much higher than the price of a 0.99 carats diamond. To study this phenomenon in more detail, we consider two random samples of diamonds, 0.99 carats and 1 carat, each sample of size 23. The average price of 0.99 carats diamonds in the sample is $4451, while the average price of 1 carat diamonds in the sample is $5681. From long-term studies, we know that both the prices of 0.99 carats diamonds and the prices of 1 carat diamonds are normally distributed with standard deviations ơ1 = $1332 (0.99 carats) and o2 = $1613 (1 carat), respectively. (a) Carry out a hypothesis test at significance level 0.01 to evaluate whether the true average price µ1 of 0.99 carats diamonds is lower than the true average price µz of 1 carat diamonds. Specify Ho and Ha, the test statistic, and calculate the p-value or use p-value considerations to conclude. (b) Compute the type II error probability for the test in (a) if the true average price of 1 carat diamonds is $5500 and the true average price of 0.99 carats diamonds is $4600. Include a detailed derivation in your answer. (c) How large do the sample sizes (kept equal for 0.99 carats and 1 carat diamonds) have to be such that, in the situation described in (b), the type II error probability is at most 5%? Include a detailed derivation in your answer.

Glencoe Algebra 1, Student Edition, 9780079039897, 0079039898, 2018
18th Edition
ISBN:9780079039897
Author:Carter
Publisher:Carter
Chapter4: Equations Of Linear Functions
Section4.5: Correlation And Causation
Problem 2CYU
icon
Related questions
Topic Video
Question

Need an answer for c) only!

Prices of diamonds are very sensitive to their weight (measured in carat). For example, the price of
a 1 carat diamond tends to be much higher than the price of a 0.99 carats diamond. To study this
phenomenon in more detail, we consider two random samples of diamonds, 0.99 carats and 1 carat,
each sample of size 23. The average price of 0.99 carats diamonds in the sample is $4451, while the
average price of 1 carat diamonds in the sample is $5681. From long-term studies, we know that
both the prices of 0.99 carats diamonds and the prices of 1 carat diamonds are normally distributed
with standard deviations ơ1 = $1332 (0.99 carats) and o2 = $1613 (1 carat), respectively.
(a) Carry out a hypothesis test at significance level 0.01 to evaluate whether the true average
price µi of 0.99 carats diamonds is lower than the true average price µ2 of 1 carat diamonds.
Specify Ho and Ha, the test statistic, and calculate the p-value or use p-value considerations
to conclude.
(b) Compute the type II error probability for the test in (a) if the true average price of 1 carat
diamonds is $5500 and the true average price of 0.99 carats diamonds is $4600. Include a
detailed derivation in your answer.
(c) How large do the sample sizes (kept equal for 0.99 carats and 1 carat diamonds) have to be
such that, in the situation described in (b), the type II error probability is at most 5%? Include
a detailed derivation in your answer.
Transcribed Image Text:Prices of diamonds are very sensitive to their weight (measured in carat). For example, the price of a 1 carat diamond tends to be much higher than the price of a 0.99 carats diamond. To study this phenomenon in more detail, we consider two random samples of diamonds, 0.99 carats and 1 carat, each sample of size 23. The average price of 0.99 carats diamonds in the sample is $4451, while the average price of 1 carat diamonds in the sample is $5681. From long-term studies, we know that both the prices of 0.99 carats diamonds and the prices of 1 carat diamonds are normally distributed with standard deviations ơ1 = $1332 (0.99 carats) and o2 = $1613 (1 carat), respectively. (a) Carry out a hypothesis test at significance level 0.01 to evaluate whether the true average price µi of 0.99 carats diamonds is lower than the true average price µ2 of 1 carat diamonds. Specify Ho and Ha, the test statistic, and calculate the p-value or use p-value considerations to conclude. (b) Compute the type II error probability for the test in (a) if the true average price of 1 carat diamonds is $5500 and the true average price of 0.99 carats diamonds is $4600. Include a detailed derivation in your answer. (c) How large do the sample sizes (kept equal for 0.99 carats and 1 carat diamonds) have to be such that, in the situation described in (b), the type II error probability is at most 5%? Include a detailed derivation in your answer.
Expert Solution
steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Discrete Probability Distributions
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897…
Glencoe Algebra 1, Student Edition, 9780079039897…
Algebra
ISBN:
9780079039897
Author:
Carter
Publisher:
McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Algebra
ISBN:
9781680331141
Author:
HOUGHTON MIFFLIN HARCOURT
Publisher:
Houghton Mifflin Harcourt