Chapter 4 Assignment

Silver Springs Moving and Storage Incorporated is studying the relationship between the number of rooms in a move and the number of labor hours required for the move. Compute a correlation coefficient.

Correlation coefficient: 0.83

Describe the differences between a histogram and a dot plot. When might a dot plot be better than a histogram?

Histogram is better for large data sets and dot plot is better for small data sets.

Study the table given below. Choose the correct description for the relationship between the values:

Larger values of x are associated with larger values of y.

Determine the median and the first and third quartiles in the following data. 5.24 6.02 6.67 7.30 7.59 7.99 8.03 8.35 8.81 9.45 9.61 10.37 10.39 11.86 12.22 12.71 13.07 13.59 13.89 15.42

Median: 9.53 First quartile: 7.69 Third quartile: 12.59

An auto insurance company reported the following information regarding for the age of a driver and the number of accidents reported for that driver last year.

The number of accidents decreases as driver age increases. The slope indicates that for each additional five years of driving experience, the number of accidents decreases about 2 per the indicated number of years of experience.

Wendy's offers eight different condiments (mustard, ketchup, onion, mayonnaise, pickle, lettuce, tomato, and relish) on hamburgers. A store manager collected the following information on the number of condiments ordered and the age group of the customer. What can you conclude regarding the information? Who tends to order the most number of condiments?

Younger people order more condiments.

McGivern Jewelers is located in the Levis Square Mall just south of Toledo, Ohio. Recently it posted an advertisement on a social media site reporting the shape, size, price, and cut grade for 33 of its diamonds currently in stock. The information is reported below. a-2. Draw a box plot of the variable price and comment on the result. Does the distribution show any outliers? a-3. What is the median price? a-4. What is the value of the first and the third quartile of the variable price? b-2. Draw a box plot of the variable size and comment on the result. Does the distribution show any outliers? b-3. What is the median size? b-4. What is the value of the first and the third quartile of the variable size? c-2. Draw a scatter diagram of the variables price and size. Plot price on the vertical axis and size on the horizontal axis. Is there an association between the two variables? c-3. Is the association direct or indirect? c-4. Does any point seem to be different from the others? d-2. Suppose a contingency table for the variables shape and cut grade is developed, what is the most common cut grade? d-3. What is the most common shape? d-4. What is the most common combination of cut grade and shape?

a-2. Yes a-3. Median: $3,733 a-4. 1st quartile: $1,478 3rd quartile: $6,141 b-2. Yes b-3. Median: .84 b-4. 1st quartile: 0.515 3rd quartile: 1.120 c-2. Yes c-3. Direct c-4. Yes d-2. Premium cut is most common cut grade. d-3. The majority of the diamonds are round. d-4. The round premium combination occurs most often.

The Director of Planning for Devine Dining Incorporated wishes to study the relationship between the time of day a customer dines and whether the guest orders dessert. To investigate the relationship, the manager collected the following information on 200 recent customers. a. What is the level of measurement of the two variables? b. What is the above table called? c. Does the data suggest that customers are more likely to order dessert? d. Does the data suggest that customers at lunch time are more likely to order dessert? e. Does the data suggest that customers at dinner time are more likely to order dessert?

a. Both variables are nominal. b. Contingency table c. Yes, 58.5%, or more than half of the customers order dessert. d. No, only 32% of lunch customers order dessert e. Yes, 85% of dinner customers order dessert.

Consider the following chart. a. What is this chart called? b. How many observations are in the study? c. What are the maximum and the minimum values? d. Around what values do the observations tend to cluster?

a. Dot plot b. There are 15 observations in the study c. Max: 7 Min: 1 d. The values cluster on 2 or 3

The Thomas Supply Company Incorporated is a distributor of gas-powered generators. As with any business, the length of time customers take to pay their invoices is important. Listed below, arranged from smallest to largest, is the time, in days, for a sample of the Thomas Supply Company Incorporated invoices. 13 13 13 20 26 26 27 31 34 34 35 35 36 37 38 41 41 41 42 43 44 47 48 49 51 55 56 62 67 82 a. Determine the first and third quartiles. b. Determine the second decile and the eighth decile. c. Determine the 67th percentile.

a. First quartile: 30.00 Third quartile: 48.25 b. Second decile: 26.20 Eighth decile: 50.60 c. 67th percentile: 43.77

Listed below are the commissions earned ($000) last year by a sample of 15 sales representatives at Furniture Patch Incorporated 4.2 6.0 7.3 10.6 13.0 13.6 14.2 15.3 16.8 17.4 18.6 22.3 36.6 43.2 79.2 a. Determine the mean, median, and the standard deviation. b. Determine the coefficient of skewness using Pearson's method. c. Determine the coefficient of skewness using the software method.

a. Mean: $21.22 Median: $15.30 Standard Deviation: $19.20 b. Coefficient of skewness: 0.925 c. Coefficient of skewness: 2.272

Listed below are the salaries, in $000, for a sample of 15 chief financial officers in the electronics industry. 516.0 548.0 566.0 534.0 586.0 529.0 546.0 523.0 538.0 523.0 551.0 552.0 486.0 558.0 574.0 a. Determine the mean, median, and the standard deviation. b. Determine the coefficient of skewness using Pearson's method. c. Determine the coefficient of skewness using the software method.

a. Mean: $542.00 Median: $546.00 Standard deviation: $25.08 b. Coefficient of skewness: -.0478 c. Coefficient of skewness: -0.375

The American Society of PeriAnesthesia Nurses (ASPAN; www.aspan.org) is a national organization serving nurses practicing in ambulatory surgery, preanesthesia, and postanesthesia care. The organization consists of the 40 components listed below. a. Find the mean, median, and standard deviation of the number of members per component. b-1. Find the coefficient of skewness, using the software method. b-2. What do you conclude about the shape of the distribution of component size? c. Determine the first and third quartiles. d-1. What are the limits for outliers? d-2. Are there any outliers?

a. Mean: 348.50 Median: 276.00 Standard Deviation: 273.94 b-1. Coefficient of skewness: 1.17 b-2. Mild positive skewness c. 1st quartile: 108.25 3rd quartile: 527.50 d-1. Limits -521 to 1,156 d-2. One

The American Society of PeriAnesthesia Nurses (ASPAN; www.aspan.org) is a national organization serving nurses practicing in ambulatory surgery, preanesthesia, and postanesthesia care. The organization consists of the 40 components listed below. a. Find the mean, median, and standard deviation of the number of members per component. b-1. Find the coefficient of skewness, using the software method. b-2. What do you conclude about the shape of the distribution of component size? c. Determine the first and third quartiles. Do not use the method described by Excel. d-1. What are the limits for outliers? d-2. Are there any outliers?

a. Mean: 354.83 Median: 266.00 Standard Deviation: 293.56 b-1. Coefficient of skewness: 1.29 b-2. Mild positive skewness c. 1st quartile: 124.00 3rd quartile: 488.25 d-1. Limits -422.4 to 1,034.6 d-2. Two

In recent years, due to low interest rates, many homeowners refinanced their home mortgages. Linda Lahey is a mortgage officer at Down River Federal Savings and Loan. Below is the amount refinanced for 20 loans she processed last week. The data are reported in thousands of dollars and arranged from smallest to largest. 59.2 59.5 61.6 65.5 66.6 72.9 74.8 77.3 79.2 83.7 85.6 85.8 86.6 87.0 87.1 90.2 93.3 98.6 100.2 100.7 a. Find the median, first quartile, and third quartile. b. Find the 26th and 83rd percentiles.

a. Median: $84.65 1st quartile: $68.18 3rd quartile: $89.43 b. 26th percentile: $69.50 83rd percentile: $95.58

The box plot shows the undergraduate in-state tuition per credit hour at four-year public colleges. a. Estimate the median. b. Estimate the first and third quartiles. c. Determine the interquartile range. d. Beyond what point is a value considered an outlier? e. Identify any outliers and estimate their values. If there are no outliers select "None". f. Is the distribution symmetrical, or positively or negatively skewed?

a. Median: 500 b. Q1: 300 Q2: 700 c. Interquartile range: 400 d. Less than 0 or more than 750 e. 1,500 f. Positively skewed

Kevin Horn is the national sales manager for National Textbooks Incorporated. He has a sales staff of 40 who visit college professors all over the United States. Each Saturday morning he requires his sales staff to send him a report. This report includes, among other things, the number of professors visited during the previous week. Listed below, ordered from smallest to largest, are the number of visits last week. 38 40 41 45 48 48 50 50 51 51 52 52 53 54 55 55 55 56 56 57 59 59 59 62 62 62 63 64 65 66 66 67 67 69 69 71 77 78 79 79 a. Determine the median number of calls. b. Determine the first and third quartiles. c. Determine the first decile and the ninth decile. d. Determine the 33rd percentile.

a. Median: 58 b. Q1: 51.25 Q3: 66 c. 1st decile: 45.3 9th decile: 76.4 d. 33rd percentile: 53.53