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Welcome to Rectangularity ! Home of the Squarely Quads. Rectangularity has a population of 100 squarely quads with various areas. Each square represents one unit towards a rectangle’s area. . What is the purpose of a confidence interval?.
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Welcome to Rectangularity! Home of the Squarely Quads
Rectangularity has a population of 100 squarely quads with various areas. Each square represents one unit towards a rectangle’s area.
What is the purpose of a confidence interval? To determine how confident you are that the population mean falls within your interval
Why are we replacing the card after each selection? to maintain independence among the sample observations
Confidence Interval Formula CI = x ± ME ME = z * (σ/√n) critical z value 1. percent of area in each tail = (1 – CI)/2 2. 2nd, VARS, 3 (invNorm), 1-%
Class Data for 80% Confidence Level • 0 1 2 3 4 5 6 7 8 91011 12 13 6.26
Class Data for 99% Confidence Level • 0 1 2 3 4 5 6 7 8 91011 12 13 6.26
An 80% confidence level means that we would expect 80% of the interval estimates to include the population parameter. 99%
A 99% confidence level means that we would expect 99% of the interval estimates to include the population parameter. It is very likely to enclose the mean of the population. It may be too wide to give us a good estimate of the value of μ.
Cards to represent the Population of Squarely Quads
Ms. 2 Ms. 4 Mr. 1 Mr. 3 Mr. 5 Mr. 7 Ms. 6 Ms. 8
Mr. 11 Mr. 13 Mr. 15 Ms. 10 Ms. 12 Ms. 14 Ms. 16 Mr. 9
Mr. 17 Mr. 19 Mr. 21 Mr. 23 Ms. 18 Ms. 20 Ms. 22 Ms. 24
Mr. 25 Mr. 27 Mr. 29 Mr. 31 Ms. 26 Ms. 28 Ms. 30 Ms. 32
Mr. 33 Mr. 35 Mr. 37 Mr. 39 Ms. 34 Ms. 36 Ms. 38 Ms. 40
Ms. 42 Ms. 44 Mr. 41 Mr. 43 Mr. 45 Mr. 47 Ms. 46 Ms. 48
Mr. 49 Mr. 51 Mr. 53 Mr. 55 Ms. 50 Ms. 52 Ms. 54 Ms. 56
Mr. 57 Mr. 59 Mr. 61 Mr. 63 Ms. 58 Ms. 60 Ms. 62 Ms. 64
Mr. 65 Mr. 67 Mr. 69 Mr. 71 Ms. 66 Ms. 68 Ms. 70 Ms. 72
Mr. 73 Mr. 75 Mr. 77 Mr. 79 Ms. 74 Ms. 76 Ms. 78 Ms. 80
Ms. 82 Ms. 84 Mr. 81 Mr. 83 Mr. 85 Mr. 87 Ms. 86 Ms. 88
Mr. 89 Mr. 91 Mr. 93 Mr. 95 Ms. 90 Ms. 92 Ms. 94 Ms. 96
Adapted by Dr. Jennifer L. Brown, Columbus State University, 2012 Original Source: (Richardson, Curtiss, Gabrosek, & Reischman, 2002) Mr. 97 Mr. 99 Ms. 98 Ms. 100