Purchase Solution

Chi square-confidence interval for the variance

Not what you're looking for?

Ask Custom Question

The owner of an Internet video supplier, Netflix, has conducted a study of the habits of online customers. In particular she wants to estimate the average number of videos checked out each month. Before she can determine the sample size she will need, she needs to make an estimate of the standard deviation. On the basis of her past experience and judgment, she estimates that the standard deviation is equal to 12. Suppose that a pilot study of 15 online customers indicates a sample standard deviation of 9.25 videos. At a 0.10 level of significance what are the critical boundaries for rejecting H0: s = 12?

X2 < -6.571 or X2 > +6.571
X2 < +6.571 or X2 > +23.685
X2 < -2.575 or X2 > +2.575
X2 < -23.865 or X2 > +23.685

Purchase this Solution
Solution Summary

Chi square distribution has been used for calculating the confidence interval for the variance.

Solution Preview

The owner of an Internet video supplier, Netflix, has conducted a study of the habits of online customers. In particular she wants to estimate the average number of videos checked out each month. Before she can determine the sample size she will need, she needs to make an estimate of the standard deviation. On ...

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.

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.

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

  • Population Variance Problem and Confidence Interval

    Suppose you wish to describe the variability of the carapace lengths of this population of lobsters. Find a 99% confidence interval for the population variance Ï?^2.

  • Confidence interval for the population standard deviation.

    sample size=n= 16 standard deviation =s= 7778 Variance of return=s 2 = 60497284 =7778 ^2 We use the chi square distribution for the confidence interval for the variance degrees of freedom=n-1= 15 =16-1 Confidence interval

  • Estimate and Interpret Population Variance

    Plugging these values into the formula for the confidence interval for , we get the confidence interval for the variance to be: [8802.02, 22766.97] Taking the square root of these endpoints, we get the confidence interval for the population standard

  • Confidence level for variance

    0.032 Confidence Level 98% Intermediate Calculations Degrees of Freedom 9 Sum of Squares 0.009216 Single Tail Area 0.01 Lower Chi-Square Value 2.087901 Upper Chi-Square Value 21.66599 Results Interval Lower Limit for Variance 0.000425

  • Confidence interval and chi square hypothesis test for variance

    We can conclude that the variance is greater than 9.4. The solution determines a confidence interval and chi square hypothesis test for variance.

  • Confidence Intervals for the Variance and Standard Deviation

    If the sample size is large then we can use F approximation √2χˆ2 ~ N( √(2N - 1) , 1) To find the confidence interval for variance using chi-square test statistic.

  • Confidence Interval, Standard Deviation and Normal Distribution

    Use the 2 (chi-squared) distribution for the confidence interval for the variance The confidence interval (C.I.) includes the area under the curve in between the critical values, excluding the tail areas (the α risk).

  • Confidence Interval Problem: Cholesterol Concentration

    Results Interval Lower Limit for Variance 1.686912543 Interval Upper Limit for Variance 4.754632781 Interval Lower Limit for Standard Deviation 1.298811974 Interval Upper Limit for Standard Deviation 2.180512046 The expert examines the cholesterol

  • Confidence interval estimation

    Chi-Square Value 35.71847 Results Interval Lower Limit for Variance 1460.749 Interval Upper Limit for Variance 9158.106 Interval Lower Limit for Standard Deviation 38.21975 Interval Upper Limit for Standard Deviation 95.698 Since the

  • Prepare a contribution format income statement

    Chi-Square Value 35.71847 Results Interval Lower Limit for Variance 1460.749 Interval Upper Limit for Variance 9158.106 Interval Lower Limit for Standard Deviation 38.21975 Interval Upper Limit for Standard Deviation 95.698 Since the

View More Related Solutions