A sample of 58 research cotton samples resulted in a sample average percentage elongation of 8.11...

A sample of 58 research cotton samples resulted in a sample average percentage elongation of 8.11 and a sample standard deviation of 1.45. Calculate a 95% large-sample CI for the true average percentage elongation μ. (Round your answers to three decimal places.)

Expert Solution

Solution :

Given that,

Point estimate = sample mean = = 8.11

Population standard deviation = = 1.45

Sample size n =58

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z / 2 = Z0.025 = 1.96 ( Using z table )

Margin of error = E = Z/2 * ( / $\sqrt$ n)
= 1.96 * ( 1.45/ $\sqrt$ 58 $\sqrt$ )

= 0.373
At 95% confidence interval
is,

- E < < + E

8.11 - 0.373 < < 8.11 + 0.373

7.737 < < 8.483

orchestra answered 1 year ago

A sample of 51 research cotton samples resulted in a sample average percentage elongation of 8.11...

A sample of 51 research cotton samples resulted in a sample average percentage elongation of 8.11 and a sample standard deviation of 1.49. Calculate a 95% large-sample CI for the true average percentage elongation μ. (Round your answers to three decimal places.) (_,_) What assumptions are you making about the distribution of percentage elongation? We assume the distribution of percentage elongation is normal with the value of σ unknown. We make no assumptions about the distribution of percentage elongation. We...

A sample of 56 research cotton samples resulted in a sample average percentage elongation of 8.16...

A sample of 56 research cotton samples resulted in a sample average percentage elongation of 8.16 and a sample standard deviation of 1.43. a. Calculate a 95% large-sample CI for the true average percentage elongation μ. (Round your answers to three decimal places.) b .What assumptions are you making about the distribution of percentage elongation? a.We assume the distribution of percentage elongation is uniform. b.We assume the distribution of percentage elongation is normal with the value of σ known. c.We...

A random sample of 81 lighting flashes in a certain region resulted in a sample average...

A random sample of 81 lighting flashes in a certain region resulted in a sample average radar echo duration of 0.8168 sec and a sample standard deviation of 0.36 sec (“Lighting Strikes to an Airplane in a Thunderstorm”, Journal of Aircraft, 1984). Calculate a 99% (two-sided) confidence interval for the true average echo duration μ.

The variables collected for this sample are average startingsalary upon graduation ($), the percentage of...

The variables collected for this sample are average starting salary upon graduation ($), the percentage of applicants to the full-time program who were accepted, the average GMAT test score of students entering the program, program per-year tuition ($), and percent of students with job offers at time of graduation.Build at least five different multiple regression models with different combinations of predictors and transformations. Provide the regression equation for each model and its Adjusted R2 and F statistic.UniversityTuition per year ($)Average...

A survey of 77 commercial airline flights of under 2 hours resulted in a sample average...

A survey of 77 commercial airline flights of under 2 hours resulted in a sample average late time for a flight of 2.60 minutes. The population standard deviation was 12 minutes. Construct a 95% confidence interval for the average time that a commercial flight of under 2 hours is late. What is the point estimate? What does the interval tell about whether the average flight is late? (Round your answers to 2 decimal places.) ≤ μ ≤ The point estimate...

The variables collected for this sample are average starting salary upon graduation ($), the percentage of...

The variables collected for this sample are average starting salary upon graduation ($), the percentage of applicants to the full-time program who were accepted, the average GMAT test score of students entering the program, program per-year tuition ($), and percent of students with job offers at time of graduation. Build a simple linear regression model with each of the predictors and the dependent variable. Provide the R2 for each simple linear regression model. Which predictor has the highest correlation with...

Identify the appropriate statistical test for each research description: Single-sample z-test Single-samplet-test Independent samples t-test Related...

Identify the appropriate statistical test for each research description: Single-sample z-test Single-samplet-test Independent samples t-test Related samples t-test (repeated measures or matched samples) Correlation A researcher investigates whether single people who own pets are generally happier than singles without pets. A group of non-pet owners is compared to pet owners using a mood inventory. The pet owners are matched one to one with the non-pet owners for income, number of close friendships, and general health.

dentify the appropriate statistical test for each research description: Single-sample z-test Single-samplet-test Independent samples t-test Related...

dentify the appropriate statistical test for each research description: Single-sample z-test Single-samplet-test Independent samples t-test Related samples t-test (repeated measures or matched samples) Correlation An office manager wants to know if there’s a gender difference in punctuality. Over the period of one month, he records the number of days that each employee is late, to see if there’s a difference between male and female employees.

Question