Confidence interval for mean and standard deviation
Not what you're looking for?
3. in an effort to estimate the annual income for new graduates, data were collected from 500 new graduates over a one -year period. assume a population standard deviation of $500.
a) if the sample mean is $15,000, what is the 95% confidence interval for the population mean?
b) if the sample mean is $15,000, what is the 98% confidence interval for the population mean?
c) discuss what happens to the width of the confidence interval as confidence level is increased. does this seem reasonable? explain.
d) if the data were collected for a sample of 25 rather than 500, develop a 95% confidence interval for the population mean (assuming the population has a normal probability distribution).
e) discuss what happens to the width of the confidence interval as the sample size decreases. does this seem reasonable? explain.
Purchase this Solution
Solution Summary
The solution provides step by step method for the calculation of confidence interval for mean . Formula for the calculation and Interpretations of the results are also included.
Purchase this Solution
Free BrainMass Quizzes
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
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.