Purchase Solution

Confidence interval for the population mean: Use of the t distribution

Not what you're looking for?

Ask Custom Question

A certain brokerage house wants to estimate the mean daily return on a certain stock. A random sample of 17 days yields the following return percentages:

1.87
2.94
1.39
-1.29
-0.51
-2.9
-2.83
1.11
1.43
-1.88
0.79
-0.97
1.13
-1.13
-2.95
1.49
-1.57

If we assume that the returns are normally distributed, find a 90% confidence interval for the mean daily return on this stock. Then complete the table below.

Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.

What is the lower limit of the confidence interval?
What is the upper limit of the confidence interval?

Purchase this Solution
Solution Summary

A certain brokerage house wants to estimate the mean daily return on a certain stock. A random sample of 17 days yields the following return percentages:

1.87
2.94
1.39
-1.29
-0.51
-2.9
-2.83
1.11
1.43
-1.88
0.79
-0.97
1.13
-1.13
-2.95
1.49
-1.57

If we assume that the returns are normally distributed, find a 90% confidence interval for the mean daily return on this stock. Then complete the table below.

Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.

What is the lower limit of the confidence interval?
What is the upper limit of the confidence interval?

Purchase this Solution
Free BrainMass Quizzes
Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

View More Free Quizzes
Related BrainMass Solutions

  • Confidence interval for the true population mean

    2 tailed because we are calculating the confidence interval) Since sample size 8 is less than 30 and population standard deviation is 'Not Known' use t distribution Thus we use t distribution t at the 0.23 level of significance

  • Finding a confidence interval for the population mean

    b) Explain why we need to use the T distribution. What assumption do you need to make? c) For a 90 percent confidence interval, what is the value of T? d) Develop the 90 percent confidence interval for the population mean.

  • Confidence interval for mean

    Use t statistic with 80 d.f . T value = 1.99 4) Construct a confidence interval of 95% for the population mean. The confidence interval is given by .

  • Population Mean - American Sugar Producers Association

    Explain why we need to use the t distribution. What assumption do you need to make? C. For a 90 percent confidence interval, what is the value of t? D. Develop the 90 percent confidence interval for the population mean. E.

  • Finding a confidence interval for the population mean

    What is the value of the population mean? What is the best estimate of this value? b. Explain why we need to use the t distribution. What assumption do you need to make? c. For a 90% confidence interval, what is the value of t? d.

  • Statistical Problems - Mean, Confidence Interval, Testing

    Explain why we need to use the t distribution. What assumption do you need to make? c. For a 95 percent confidence interval, what is the value of t? d. Develop the 95 percent confidence interval for the population mean. e.

  • Confidence interval for the population mean

    Confidence interval for the population mean: Use of the t distribution A corporation that maintains a large fleet of company cars for the use of its sales staff is interested in the mean distance driven monthly per sales person.

  • Finding probabilities based on a sample

    a. what is the value of the population mean? what is the best estimate of this value? b. explain why we need to use the t distribution. what assumption do yo uneed to make? c. for a 95 percent confidence interval, what is the value of t?

  • Mean Yearly Sugar Consumption

    This solution explains the best estimate of the population mean and the appropriate usage of the t-distribution. It also calculates the t value for a 90% confidence interval and the confidence interval for the population mean.

  • Confidence Interval

    Determine t value for 90% confidence: Use Student's t distribution table to determine t, using df =7 and α = .05 Therefore, t.05 = 1.895 Note: α = .025 because it represents either the lower or upper end of the confidence interval. 4.

View More Related Solutions