Question

A study of the ages of motorcyclists killed in crashes involves the random selection of 132

drivers with a sample mean of 32.95 years. Assume that the population standard deviation is 9.4 years. a) Find the critical value zα /2 for a 94% confidence interval

b) Construct and interpret the 94% confidence interval estimate of the mean age of all motorcyclists killed in crashes. Use the z-table method.

c) Use TI84/83 calculator method.

d) Write a conclusion about the confidence interval.

Answer #1

**A.**

= 1.881

**B.**

**C.**

Follow the below stop to calculate the confidence interval:

Press [STAT]->Calc->7. Z-interval [ENTER]

**D.**

Therefore, based on the data provided, the 94% confidence interval for the population mean is 31.411<μ<34.489, which indicates that we are 94% confident that the true population mean age of all motorcyclists killed in crashes is contained by the interval (31.411,34.489).

**Please upvote if you have liked my answer, would be of
great help. Thank you.**

A study of the ages of motorcyclists killed in crashes involves
the random selection of 149 drivers with a mean of 33.24years.
Assuming that sigmaσequals=8.2 years, construct and interpret a
90% confidence interval estimate of the mean age of all
motorcyclists killed in crashes.

A study of the ages of motorcyclists killed in crashes involves
the random selection of 143 drivers with a mean of 38.01 years.
Assuming that sigmaequals8.8 years, construct and interpret a 99%
confidence interval estimate of the mean age of all motorcyclists
killed in crashes.What is the 99% confidence interval for the
population mean u?

Randomly selected statistics students of the author participated
in an experiment to test their ability to determine when 60 seconds
has passed. Forty students yielded a sample mean of
57.3 sec. Assume that the population standard deviation is σ =
8.5 sec.
a) Find the critical value zα /2 for a 82% confidence
interval
b) Construct a 82% confidence interval estimate of the
population mean of all statistics students. Use the z-table
method.
c) Use TI84/83 calculator method.
d) Write...

The following data lists the ages of a random selection of
actresses when they won an award in the category of Best? Actress,
along with the ages of actors when they won in the category of Best
Actor. The ages are matched according to the year that the awards
were presented. Complete parts? (a) and? (b) below.
Actress(years) 31 31 31 32 36 28 29 40 31 35
Actor (years) 60 34 38 40 29 35 51 35 38 40...

The following data lists the ages of a random selection of
actresses when they won an award in the category of Best Actress,
along with the ages of actors when they won in the category of Best
Actor. The ages are matched according to the year that the awards
were presented. Complete parts (a) and (b) below. Actress left
parenthesis years right parenthesisActress (years) 2626 2727 3030
2626 3434 2424 2727 3838 3131 3333 Actor left parenthesis years
right parenthesisActor...

Randomly selected 30 student cars have ages with a mean of 7
years and a standard deviation of 3.6 years, while randomly
selected 23 faculty cars have ages with a mean of 5.9 years and a
standard deviation of 3.5 years.
1. Use a 0.01 significance level to test the claim that student
cars are older than faculty cars.
(a) The test statistic is
(b) The critical value is
(c) Is there sufficient evidence to support the claim that
student...

(1 point) Randomly selected 14 student cars have ages with a
mean of 8 years and a standard deviation of 3.6 years, while
randomly selected 19 faculty cars have ages with a mean of 6 years
and a standard deviation of 3.3 years. 1. Use a 0.01 significance
level to test the claim that student cars are older than faculty
cars. (a) The test statistic is (b) The critical value is (c) Is
there sufficient evidence to support the claim...

Randomly selected 130 student cars have ages with a mean of 7.9
years and a standard deviation of 3.4 years, while randomly
selected 65 faculty cars have ages with a mean of 5.7 years and a
standard deviation of 3.3 years. 1. Use a 0.02 significance level
to test the claim that student cars are older than faculty cars.
The test statistic is The critical value is Is there sufficient
evidence to support the claim that student cars are older...

Randomly selected 17 student cars have ages with a mean of 7
years and a standard deviation of 3.6 years, while randomly
selected 20 faculty cars have ages with a mean of 5.6 years and a
standard deviation of 3.7 years.
1. Use a 0.05 significance level to test the claim that student
cars are older than faculty cars.
(a) The test statistic is
(b) The critical value is
(c) Is there sufficient evidence to support the claim that
student...

A sample of 17 randomly selected student cars have ages with a
mean of 7.8 years and a standard deviation of 3.6 years, while a
sample of 22 randomly selected faculty cars have ages with a mean
of 5.6 years and a standard deviation of 3.3 years.
1. Use a 0.05 significance level to test the claim that student
cars are older than faculty cars.
(a) The test statistic is 1.9619
(b) The critical value is 1.688
(c) Is there...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 3 minutes ago

asked 7 minutes ago

asked 10 minutes ago

asked 23 minutes ago

asked 28 minutes ago

asked 30 minutes ago

asked 31 minutes ago

asked 37 minutes ago

asked 40 minutes ago

asked 42 minutes ago

asked 46 minutes ago

asked 51 minutes ago