Practice Problems (Describing Data Using Numerical Measures) 1. Henderson JMK Lawncare provides yard care services for customers throughout the Henderson and Las Vegas area. The company's owner recently tracked the time his field employees spent at a sample of customer locations. He was hoping to use this data to help him with scheduling and billing rates. Use his data below to answer a-f. 10 11 13 14 17 17 17 18 20 21 22 22 22 22 22 23 23 24 25 25 26 26 26 27 27 27 28 29 29 29 29 29 29 30 31 32 34 37 38 38 a. What is the Mean? b. What is the Median? c. What is the Mode? d. Based on these 3 measures of Central Tendency, what is the shape of the distribution? Explain how you know. e. Which measure of central tendency would be most appropriate for making decisions about scheduling and billing rates? Explain based on the shape of the distribution and the scale of measurement. f. If the owner of Henderson JMK Lawncare wants to question his field workers who had a time on the job in the 80th percentile or higher (to see what took so long), which times would qualify? Practice Problems (Describing Data Using Numerical Measures) Page 1 2. Arville Professional Building, a commercial real estate company located in Las Vegas Nevada, owns 6 office buildings that it leases to local businesses. The lease price per square foot depends on the desirability of the location and the amenities in the building. The owner knows the price per square foot for each building and how many square feet each building is (see data below). However, the owner wants to present the overall mean price per square foot for all of the buildings Arville Professional Building owns at an upcoming real estate convention. What is the weighted mean? Price Per Square Foot Number of Square Feet Building 1 $75 125,000 Building 2 $85 37,500 Building 3 $90 77,500 Building 4 $45 35,000 Building 5 $55 60,000 Building 6 $110 130,000 Practice Problems (Describing Data Using Numerical Measures) Page 2 3. Mechelle and Betty are both Administrative Assistants for Mark Frissora (the CEO of Caesars Entertainment Corporation). He has been receiving complaints about grammatical errors in emails being sent in his name (by his Administrative Assistants) and wants to find out who the likely culprit is. Mark begins keeping track of who sends emails under his name and collects data for a sample of 14 emails (7 from Mechelle and 7 from Betty) with the data below (use to answer a.- e.). Mechell e 5 5 4 7 4 7 5 Betty 0 3 2 2 1 0 3 a. Calculate the mean for both Administrative Assistants. X X Mechelle Betty = = b. What is the median for both Administrative Assistants? Mdn.Mechelle = Mdn.Betty = c. What is the mode for both Administrative Assistants? ModeMechelle = ModeBetty = d. Who has a higher overall number of errors, explain based on your measures of central tendency using Plain English? Practice Problems (Describing Data Using Numerical Measures) Page 3