Purchase Solution

Sample Size, Margin of Error, Confidence Level

Not what you're looking for?

Ask Custom Question

Sample Size, Margin of Error, Confidence Level. See attached file for full problem description.

Attachments
Purchase this Solution
Solution Summary

Answers questions on Sample Size, Margin of Error, Confidence Level etc.

Solution Preview

1

Confidence level= 98%
or Significance level alpha (a) = 0.02
No of tails= 2
Z value corresponding to 0.02 significance level and 2 tails= 2.3263

Answer: Zc= 2.3263

2 Margin of error= 3-2.7= 0.3

3 Sample size

Standard deviation =s= 17
confidence interval= 99%
Z corresponding to 99% and two tailed test is 2.5758
We have to ensure that Z* sx < 2
or sx < =2/Z
or sx < 0.776458 =2/2.5758
But
sx=standard error of mean=s/square root of n
s= 17

or n=(s^2)/(sx^2)= 480 =17^2/0.776458^2

Answer: sample size = 480

4
Standard deviation =s= 3.6
sample size=n= 10
sx=standard error of mean=s/square root of n= 1.1384 = ( 3.6 /square root of 10)
Significance level=alpha (a) = 0.1 =1-0.9
No of tails= 2

Since sample size= 10 < 30
and we are estimating the population standard deviation from sample standard deviation
we will use t distribution
t at the 0.1 level of significance and 9 degrees of freedom (=n-1) and2 tailed test= 1.8331
...

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.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

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.

Measures of Central Tendency

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

View More Free Quizzes
Related BrainMass Solutions

  • Sample Size, Margin of error

    241546 Sample Size, Margin of error I) Find the minimum sample size you should use to assure that your estimate of p will be within the required margin of error around the population p. 1) margin of error:0.01; confidence level:95%; from a prior study

  • Confidence Interval Concepts

    The formula is given by, , where is the sample mean σ is the population standard deviation n is the sample size is the critical value at the confidence level is the margin of error (a) Increase the confidence level When the confidence level

  • Statistics Problem About Sample Size

    If we double our confidence level, what happens (numerically) to the sample size? b. If we cut our margin of error (E) in half, what happens (numerically) to the sample size? c. What size sample would you need to have 0 margin of error (i.e.

  • Confidence Interval and Sample Size Calculations

    Solution: Hypothesized Sample Proportion, p=0.5 Margin of Error, E=0.035 For 90% confidence: zα2 for 90% confidence level=1.645 Sample Size, n =zα22×p1−pE2=1.6452×0.5×1−0.50.0352=552.25≈552 For 95% confidence: zα2 for 95% confidence level=1.960

  • Value sample and interval

    When the sample size (n) decreases, the margin of error will increase and hence the width of the confidence interval increases.

  • Minimum sample size given margin of error

    Use the given margin of error, confidence level, and population standard deviation (o) to find the minimum sample size required to estimate an unknown population means (u) Margin of error: 0.5 inches, confidence level: 90%, o=2.7 inches A confidence

  • Normal distribution

    The margin of error for the study was reported at 4% points. Is the reported margin of error consistent with the sample size?

  • Sample Size & Margin of Error

    Here = 2.575829304, p = 0.10, n = 4719 Therefore, margin of error, E = = 0.011248985 Details Margin of Error Data Sample Size 4719 Number of Successes 471.9 Confidence Level 99% Intermediate Calculations Sample Proportion 0.1 Z

  • Confidence Interval & Sample Size

    Hence when sample size increases, margin of error decreases and vice-versa. 1(c)(i) The sample size is given by where p is 0.32 Sample Size Determination Data Estimate of True Proportion 0.32 Sampling Error 0.03 Confidence Level 95%

View More Related Solutions