Hypothesis Testing & Confidence Interval
Not what you're looking for?
Please see the attached problem.
A manufacturing company produces water filters for home refrigerators. The process has typically produced about 4% defective. A recently designed experiment has led to changing the seal to reduce defects. With the process running using the new seal, a random sample of 300 filters yielded 7 defects.
a. Conduct the most appropriate hypothesis test using a 0.10 significance level.
b. Construct a 90% confidence interval for the true proportion of defective water filters.
Purchase this Solution
Solution Summary
The following solution provides a step by step method for the calculations required to test hypotheses and confidence intervals for population proportions. Formulas for the calculation and interpretations of the results are also included. An interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.
Solution Preview
Answers
a. Here we need to test whether the defective filters reduced with the seal change. Hence lower tailed z-test for proportion is most appropriate.
The null hypothesis tested is
H0: The proportion of defective water filters after the seal change ≥ 0.04. (p≥0.04)
The alternative hypothesis is
H1: The proportion of defective water filters after the seal change < 0.04. (p<0.04)
The test statistic used is
Rejection criteria: ...
Purchase this Solution
Free BrainMass Quizzes
Measures of Central Tendency
Tests knowledge of the three main measures of central tendency, including some simple calculation questions.
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.