The average salary of 81 random employees in a certain financial sector was 3400 USD. From past information, we canassume that the standard deviation of the population is 450 USD. We are interested in the 90% confidence interval for thepopulation mean. What is the value of the standard error?Select one:O a. 50O b. 40O c. 60O d. 30

Population standard deviation=450 Sample size =81

Answered: The average salary of 81 random…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

The Statistics Games are played by a large number of teams across the county. Teams raise money to cover expenses incurred by participating. You want to estimate the mean amount of money raised by teams. You take a random sample of 36 teams and find a mean of $375, with a standard deviation of $32. What critical value should you use for a 95% confidence interval?
Tina catches a 14-pound bass. She does not know the population mean or standard deviation. So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds. Find the t and calculate a 95% (α = .05) confidence interval.
A researcher is interested in finding a 90% confidence interval for the mean number of times per day that college students text. The study included 97 students who averaged 25.5 texts per day. The standard deviation was 20.5 texts. Round answers to 3 decimal places where possible. b. With 90% confidence the population mean number of texts per day is between ______ and _______ texts. c. If many groups of 97 randomly selected members are studied, then a different confidence interval would be produced from each group. About _______ percent of these confidence intervals will contain the true population number of texts per day and about ___________ percent will not contain the true population mean number of texts per day.
In a survey, 28 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $45 and standard deviation of $14. Construct a confidence interval at a 99% confidence level. Give your answers to one decimal place. ________+________
Suppose we wish to study the average income of Cactus Club customers, so we plan to conduct a research project with a 95% confidence level. We need our range of error (E) to be no greater than $500. Based on our past experience, we estimate the sample standard deviation to be $5,000. What sample size do you need in order to conduct the research? Select one: a. 372 b. 784 c. 824 d. 385 e. 196
A professor was curious about her students' grade point averages. She took a random sample of 15 students and found a mean GPA of 3.01 with a standard deviation of 0.534. Which of the following formulas gives a 99% confidence interval for the mean GPA of the professor's students?
Which type of confidence interval should you use in this situation? A sample of 25 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. The distribution is approximately normally distributed. Find the 90% confidence interval for the average days worked of all payroll departments. Question 2 options: 1) a confidence interval for the mean using a table value from the standard normal distribution. 2) a confidence interval for the mean using a table value from the t distribution. 3) a confidence interval for a proportion using a table value from the standard normal distribution. 4) a confidence interval for proportion using a table value from the t distribution. 5) none of the above.
A researcher is interested in finding a 90% confidence interval for the mean number of times per day that college students text. The study included 149 students who averaged 34.2 texts per day. The standard deviation was 18.6 texts. Round to 3 decimals. b. With 90% confidence the population mean number of texts per day is between _______ and ________ texts a day.
Determine if the following statements are true or false. a. Jane took a sample of n = 100 observations from a population with mean and standard deviation. Mike also took a sample of n = 200 observations from the same population. Then, Mike’s sample mean will be closer to the true population mean than Jane’s sample. b. Jane took a sample of n = 100 observations from a population with mean and standard deviation. Mike also took a sample of n = 200 observations from a population with mean and standard deviation 2. Then, the sample mean from Mike’s sample is more likely to be close to the true mean than the sample mean from Jane’s sample. That is, the probability that X is between 90% and 110% of mean is higher for Mike’s sample than for Jane’s sample.
A psychology teacher gave an objective-type test to a class of 400 students and, after seeing the results, decided that the scores were normally distributed. The mean score was 46, and the standard deviation was 15. The teacher assigned a grade of A to all scores of 76 or over, B to scores of 61 to 75, C to scores of 31 to 60, D to scores of 16 to 30 and F to scores below 16. About how many of each grade did the teacher assign? (Round your answers to the nearest whole number. Due to rounding, values may not add to the given sum. Recall that 34% of z-scores lie between 0 and 1, 13.5% lie between 1 and 2, and 2.5% are greater than 2.) A B C D F

Recommended textbooks for you

A First Course in Probability (10th Edition)

Probability

ISBN:

9780134753119

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability

Probability

ISBN:

9780321794772

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability (10th Edition)

Probability

ISBN:

9780134753119

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability

Probability

ISBN:

9780321794772

Author:

Sheldon Ross

Publisher:

PEARSON

SEE MORE TEXTBOOKS