In 2015, the average duration of long-distance telephone calls from a certain town was 3.9 minutes. A telephone company wants to perform a test to determine whether this average duration of longdistance calls has changed. Fifty calls, originating from the town, was randomly selected and the following summary minutes.

Glencoe Algebra 1, Student Edition, 9780079039897, 0079039898, 2018
18th Edition
ISBN:9780079039897
Author:Carter
Publisher:Carter
Chapter10: Statistics
Section10.5: Comparing Sets Of Data
Problem 13PPS
icon
Related questions
Topic Video
Question
100%

Please answer  what you can

Question 2
In 2015, the average duration of long-distance telephone calls from a certain town
was 3.9 minutes.
A telephone company wants to perform a test to determine whether this average
duration of longdistance calls has changed. Fifty calls, originating from the town,
was randomly selected and the
following summary minutes.
Σx= 205 Σ (x-
2 = 56.43
a) Calculate the sample mean, x.
b) Calculate the sample standard deviation
c) Using the p value approach at the 1% level of significance, test whether the
mean duration of
long-distance calls from the town had increased.
d) Construct the 99% confidence interval for the population mean duration of the
long-distance calls from the town.
Transcribed Image Text:Question 2 In 2015, the average duration of long-distance telephone calls from a certain town was 3.9 minutes. A telephone company wants to perform a test to determine whether this average duration of longdistance calls has changed. Fifty calls, originating from the town, was randomly selected and the following summary minutes. Σx= 205 Σ (x- 2 = 56.43 a) Calculate the sample mean, x. b) Calculate the sample standard deviation c) Using the p value approach at the 1% level of significance, test whether the mean duration of long-distance calls from the town had increased. d) Construct the 99% confidence interval for the population mean duration of the long-distance calls from the town.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 1 images

Blurred answer
Knowledge Booster
Research Design Formulation
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