The average age of cars owned by residents of a small city is 6 years with...

The average age of cars owned by residents of a small city is 6 years with a standard deviation of 2.2 years. A simple random sample of 400 cars is to be selected, and the sample mean age of these cars is to be computed. What is the probability that the average age of the 400 cars is more than 6.1 years? Show all main steps of your calculation. (No points will be given to an answer of only a final number provided even if the number is correct.)

Solutions

Expert Solution

µ = 6

sd = 2.2

n = 400

= P(Z > -0.909)

= 1 - P(Z < -0.909)

= 1 - 0.1817

= 0.8183

orchestra answered 1 year ago

Next > < Previous

Related Solutions

7. A group of university students are interested in comparing the average age of cars owned...

7. A group of university students are interested in comparing the average age of cars owned by students and the average age of cars owned by faculty. They randomly selected 25 cars that are own by students and 20 cars that are owned by faculty. The average age and standard deviation obtained from the students’ cars are 6.78 years and 5.21 years, respectively. The sample of faculty cars produced a mean and a standard deviation of 5.86 years, and 2.72....

The population of a City and Average Annual Income of City Residents.

Quantitative Project research paper The population of a City and Average Annual Income of City Residents.

The average retirement age in America is 64 years old. Do small business owners retire at a different average age?

The average retirement age in America is 64 years old. Do small business owners retire at a different average age? The data below shows the results of a survey of small business owners who have recently retired. Assume that the distribution of the population is normal. 57, 65, 50, 57, 65, 63, 63, 59, 54, 66, 53, 51, 68 What can be concluded at the αα = 0.01 level of significance? For this study, we should use: t-test for a...

The city of Irvine reported that approximately 75% of residents are over the age of 60....

The city of Irvine reported that approximately 75% of residents are over the age of 60. Let X be the number of Irvine residents over the age of 60. From a random sample of 500 Irvine residents, 350 were over the age of 60. What is the sampling distribution of the sample proportion for the sample size of 500? Using the distribution of X from above, what is the probability that at most 350 of the 500 Irvine residents selected...

Following are age and price data for 10 randomly selected cars between 1 and 6 years...

Following are age and price data for 10 randomly selected cars between 1 and 6 years old. Here, x denotes age, in years, and y denotes price, in hundreds of dollars. Use the information to complete parts (a) through (g). x 6 6 6 2 2 5 4 5 1 4 y 280 290 295 425 379 315 355 333 420 325 a. Find the regression equation for the data points. y=__+(__)x

The average monthly electric bill of a random sample of 256 residents of a city is...

The average monthly electric bill of a random sample of 256 residents of a city is $90 with a standard deviation of $24. Construct a 95% confidence interval for the mean monthly electric bills of all residents. (Round to two decimal places) [Answer, Answer] Construct a 99% confidence interval for the mean monthly electric bills of all residents. (Round to two decimal places) [Answer, Answer]

You are planning to conduct a study to determine whether the average age of the residents...

You are planning to conduct a study to determine whether the average age of the residents of Ashland, OR is at least 55.6 years. What is the most appropriate test for conducting the test? One population mean test Two population means test One-way ANOVA Two-way ANOVA with Replication Chi-square Goodness of Fit Test Chi-square Test for Independence Regression and Correlation Analysis A market research firm is testing consumer reaction to a new shampoo among age groups in four regions. There...

A random sample of 31 residents in a particular city indicates an average annual income of...

A random sample of 31 residents in a particular city indicates an average annual income of $51,950 with a sample standard deviation of $7,785. Construct a 95% confidence interval to estimate the true average annual income for all residents in the city. Do not round intermediate calculations. Round your final answers to 2 decimal places. Omit the "$" sign. Lower bound for confidence interval = dollars, Upper bound for confidence interval = dollars.

The average retirement age in America is 66 years old. Do small business owners retire at...

The average retirement age in America is 66 years old. Do small business owners retire at a different average age? The data below shows the results of a survey of small business owners who have recently retired. Assume that the distribution of the population is normal. 57, 53, 72, 53, 67, 71, 65, 67, 59, 68, 69 What can be concluded at the the αα = 0.01 level of significance level of significance? For this study, we should use.... Select...

A student researcher compares the ages of cars owned by students and cars owned by faculty...

A student researcher compares the ages of cars owned by students and cars owned by faculty at a local state college. A sample of 212212 cars owned by students had an average age of 8.588.58 years. A sample of 180180 cars owned by faculty had an average age of 8.958.95 years. Assume that the population standard deviation for cars owned by students is 2.292.29 years, while the population standard deviation for cars owned by faculty is 3.583.58 years. Determine the...

Subjects