Chapter 15 Basic Statistics

§15.1 thru 15.4 – Graphs Bar graphs – Example 1 p. 483 – Problems 15.1 #18, 20, 22 (p. 483) Circle graphs – Figure 15.2 p. 485 – Example 1 p. 485 – Problems 15.2 #12, 16 (p. 487) Line graphs – Example 1 p. 488 – Problems 15.3 #2, 4 (p. 489 – 490) Other graphs – Examples 1 and 2 p. 491 – Problems 15.4 #5, 10 (p. 492)

§15.5 thru 15.6 – Averages and Percentiles Averages (Central Tendency) – Finding a number which describes a set of data – 3 general methods Mean Median Mode

§15.5 thru 15.6 – Averages and Percentiles The Mean – The Mean of a set of numbers is found by adding all of the numbers together, and dividing by the amount of numbers. The Median – The Median of an ordered set of numbers is the middle number (if there is no middle number, then the median is the mean of the two middle numbers). The Mode – The Mode of a set of numbers is the most frequently occurring number. There may be more than one mode.

§15.5 thru 15.6 – Averages and Percentiles Examples: – 13 students took an exam, with the following scores. Find the mean, median, and mode score. 98, 92, 90, 85, 85, 82, 77, 76, 75, 74, 74, 68, 52 – 10 people were surveyed for their salary. The following data was collected. Find the mean, median, and mode salary. 35,000,00059,500 99,50055,300 88,30030,200 67,20025,400 60,00022,000

§15.5 thru 15.6 – Averages and Percentiles Percentiles – Dividing a set into 100 parts and determining where a particular element falls – Example 4 p. 495

§15.9 – Statistical Process Control Mean control chart – Data plotted over time – Center line – target value – Control lines – show upper and lower tolerances Complicated formula to determine control lines – Process is out of control if: Any point is outside a control line 9 or more consecutive points fall on one side of the control line – Figure 15.8 p. 506 – No problems assigned from this section (need S x )