# Interquartile Range

### Range, Interquartile Range, Variance, Standard Deviation

The Los Angeles Times regularly reports the air quality index for various areas of Southern california. A sample of air quality index values for Pomona provided the following data: 28, 42, 58, 48, 45, 55, 60, 49, and 50. 1. Compute the range and interquartile range. 2. Compute the sample variance and sample standard deviat

### Percentile rank and inter-quartile range: Example question

For a normally distributed test with a mean of 100 and standard deviation of 20: a) What score would be associated with the 80th percentile? b) What would the inter-quartile range be for the test? c) What would be the percentile rank of a score of 125? Please give detailed notes explaining the steps required to answer ea

### Finding Interquartile Range, Outliers and 5-Number Summary

Instead of considering a data value to be an outlier if it is "very far away from most of the other data value," consider an outlier to be a value that is above Q3 by an amount greater than 1.5 X IQR or below Q1 by an amount greater than 1.5 X IQR. Use the data set given below and find the following: a. 5-number summar

### Box and Whisker Plot and Interquartile Range

5 6 7 7 7 7 8 8 8 8 8 9 9 9 9 9 9 9 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 12 12 12 12 13 13 13 13 13 13 14 14 14 14 14 15 a) Make a whisker plot and find interquartile range b) Kap has a

### Statistics Interquartile Range

Carl and Angela both work at a computer store. Each salesperson recorded the number of computers sold each month for a year. Box-and-whisker plots representing the number of computers sold per month are shown at the right. a. What is the interquartile range of Carl's sales? b. What is the

### Semi-interquartile Standard deviation and Variance

For the following set of data, find the range and the semi-interquartile range. 3,5,3,2,8,4,6,7,1,4,3,2 Calculate the variance and the standard deviation for the following sample data. 2, 3, 2, 4, 7, 5, 3, 6, 4

### Summary, Interquartile Range, and Outliers

The following data shows the waiting times in minutes for the customers in a bank before the customer is served. Waiting times: 0.38 2.34 3.02 3.20 3.54 3.79 4.21 4.50 4.77 5.12 5.13 5.55 6.10 6.19 6.46 a) Write the five number summary (the minimum, Q1, Median, Q2, and the maximum.) b) What is