Purchase Solution

Part II: Short Answers and Computational Questions

Not what you're looking for?

Ask Custom Question

1. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 175 was taken, and the mean amount spent was $250. Assuming a standard deviation equal to $45, find the 95% confidence interval for mu, the mean for all such families.

2. What sample size would be needed to estimate the population mean to within one-third standard deviation with 95% confidence?

3. A 95% confidence interval estimate for a population mean was computed to be (63.4 to 68.2). Determine the mean of the sample, which was used to determine the interval estimate.

4. In testing the hypothesis, H0: mu >= 31.5 and Ha: mu < 31.5, using the p-value approach, a p-value of 0.0409 was obtained. If sigma = 8.7, find the sample mean which produced this p-value given that the sample of size n = 50 was randomly selected.

5. To test the null hypothesis that the average lifetime for a particular brand of bulb is 725 hours versus the alternative that the average lifetime is different from 725 hours, a sample of 100 bulbs is used. If the standard deviation is 50 hours and alpha is equal to 0.01, what values for Xbar will result in rejection of the null hypothesis.

6. Describe the action that would result in a type I error and a type II error if each of the following null hypotheses were tested.

a. H0: There is no waste in US Defense Department spending
b. H0: This fast-food menu is not low fat

7. By measuring the amount of time it takes a component of a product to move from one workstation to the next, an engineer has estimated that the standard deviation is 5.1 seconds.

a. How many measurements should be made in order to be 95% certain that the maximum error of estimation will not exceed 1.5 seconds?
b. What sample size is required for a maximum error of 2.5 seconds?

8. Determine the critical region and critical values for z that would be used to test the null hypothesis at the given level of significance, as described in each of the following:

a. H0: mu =< 51 and Ha: mu > 51, alpha = 0.10
b. H0: mu >= 28 and Ha: mu < 28, alpha = 0.01
c. H0: mu = 93 and Ha: mu =/= 93, alpha = 0.05

Attachments
Purchase this Solution
Solution Summary

The solution provides step by step method for calculating confidence intervals and proving the hypothesis tests. The formula for the calculation and interpretations of the results are also included in an attached Word and Excel file.

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

  • Statistics True or False

    Sampling that subdivides the population into subgroups with like characteristics is called A) cluster B) random C) stratified D) sequence Part II Short Answers/Computational Questions 1.

  • ANOVA: Sum of Suares

    Now, compute SSbetween with the computational formula using the T values (Equation 13.7). You should obtain the same result as in part b.

  • Compute 3 treatment solutions for SS

    How to procedure for 3 treatments solution Treatments I II III n = 10 n = 10 n = 10 M = 2 M = 3 M = 7 T = 20 T =30 T = 70 Answers A.

  • Statistics: Hypothesis Tests

    Ha:   8.2 Part II. Short Answers & Computational Questions 1. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children.

  • Basic Statistics

    Presenting one qualitative and one quantitative variable C. Presenting two quantitative variables D. All of the above Part II Short Answers and Computational Questions 1.

  • Basic Statistics

    A. 50% B 95% C. 68% D. 99.7% Part II Short Answers and Computational Questions 1. What is the relationship between the variance and the standard deviation?

  • Probability - True and False

    A. n = 50, p = 0.01 B. n = 500, p = 0.001 C. n = 100, p = 0.05 D. n = 50, p = 0.02 Part II. Short Answers & Computational Questions 1. Find the following probabilities: a.

  • Compute SS for a set of 3 treaetment means

    Now, compute SSbetween with the computational formula using the T values (Equation 13.7). You should obtain the same result as in part b.

  • Transition Diagram for Automaton

    by the given automaton: yxy, yyx, xyxy, yxxy, yyxx, yyxyx, yxyyyxy, yyyyxyyyxx Response briefly explains the logic behind answer in part (iv), and it gives more than 5 strings in part (iii) that correspond to same inputs in part (ii).

  • Probabilities and Normal Distributions

    A. n = 100, p = 0.04 B. n = 50, p = 0.09 C. n = 75, p = 0.06 D. n = 12, p = 0.45 Part II. Short Answers & Computational Questions 1. Find the following probabilities: a.

View More Related Solutions