A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 55 students' scores on the exam after completing the course: 10,9,20,13,1210,9,20,13,12 Using these data, construct a 99%99% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Copy Data Step 3 of 4 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 55 students' scores on the exam after completing the course:
10,9,20,13,1210,9,20,13,12
Using these data, construct a 99%99% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal.
Copy Data
Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
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