Solve the following word problems for the unknown. Round decimals to hundredths and p ercents to the nearest tenth when necessary. Last year Keystones corporate jet required $23,040 in maintenance and repairs. a. If this represents 32% of the total operating costs of the airplane, what was the total cost to fly the plane for the year?b. If the plane flew 300,000 miles last year, what is the cost per mile to operate the plane?c. Sky King Leasing offered a deal whereby it would operate the plane for Keystone for only $0.18 per mile. What is the percent decrease in operating expense per mile being offered by Sky King?d. In 2009, the company began looking to buy another jet. Use the chart More Jets for Sale to calculate the rate of increase of jets available in 2009 compared with 1999. Round to the nearest whole percent.
Statistics 1100 Week 1 01/27/2016 ▯ Stem-and-Leaf Display ▯ Histogram for exam data (C2, Exam Scores) How many classes to use o <50 observations 5-10 classes ex: sample size: 25 (n) #classes 5-10 What is the range o Largest observation – smallest observation = range 88.40-21.10 but DON’T WANT DECIMALS 90 – 20 = 70 (good whole number) Width of class interval o Range/ number of classes = class width 70 / 7 = 10 Class frequency o # of observations in class ▯ ▯ Histogram (Frequency/ # of observations) with 7 classes Range = 90- 20= 70 Width= 10 Classes= 7 o No gaps in histogram like bar chart!! ▯ ▯ Shapes of Histogram Symmetrical Positively skewed Negatively skewed Bell-shaped ▯ ▯ Relative Frequency Hisogram with 7 classes Class relative frequency= class frequency/sample size o Class frequency =1 sample size= 25 o 1/25= .04 (relative frequency) ▯ ▯ Histogram with 5 classes 40/5 = 14 class width ▯ Histogram with 6 classes 20-92 o range 72 o 72/6= 12 class width ▯ ▯ Stem and Leaf Display 2 | 1
