SD and Normal Distribution Worksheet

Multiple Choice Warm-up to go with SD and Normal Distribution Worksheet

1) 2) 3) 4) There is no 5 and 6. #1) 28 31 34 35 37 41 42 42 42 47 49 51 52 52 60 61 67 72 75 77 #3) Age: 18 19 20 21 22 23 24 25 32 Number of students:14 120 200 200

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Quiz on 2.4 and 2.5 Next class! • Make sure you understand cummulative percentile graphs • Understand normal distribution problems: know how to draw the curve with labels. • Know how to solve the for the percentile or proportion of data between or below a number in distribution curve.

2.5 H.W. #63 - 65 63) i. 0.6318 or 63.18% ii. 0.0394 or 3.94% iii. 0.3101 or 31% 64) Mean is 511 and the standard deviation is 112 The college is looking for the top 20% or 80th percentile or above. You could use invNorm(0.8, 511, 112) = 605 OR estimated using the 68, 95, 99.7 rule. From 0 to the mean of 511 is 50% of the scores, plus 1 SD would make it 84% (near the 80th percentile) 511+ 112= 623 65) For males normalcdf (62, 72, 70.1, 2.5) = 0.7758 or 77.6% For females normalcdf(62,72,64.8,2.5) = 0.8667 or 86.7%

Student of the day! Block 4

Student of the day! Block 5

Student of the day! Block 6

Chebychev’s Rule Re-visited

#6 of Multiple Choice Yesterday A set of 5,000 scores on a college readiness exam with a mean of 72 and an s.d. of 6. If the scores are not normally distributed, what can be said of the scores less than 58. First: Use z-score to find how many s.d. 58 is from the 58  72  14 mean.    2.33 6 6 Using Chebyshev’s rule for what is NOT within 2.33 s.d. 1 from the mean:  18 .37 % 2 2.33 This is above 2.33 and below 2.33; 18.37% of 5,000 is 918 students ….that is the closest to the correct answer that can be chosen since the curve is not normally distributed.

#10 of Multiple Choice use InvNorm

The mean was 2.05 with an s.d. of 1, to the nearest tenth what was a score of someone in the 90th percentile. InvNorm reverses normalcdf InvNorm (when mean and s.d. are entered) give the proportion below that value.

InvNorm(.9, 2.05, 1) = 3.33 or choice B

Review Answers

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Answers to Multiple Choice continued… d

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Answer to multiple choice

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Using the z-score table.

SD and Normal Distribution Worksheet Problem #1

SD and normal distribution worksheet Problem #3

Draw and label the bell curve for both cows.

SD and normal distribution worksheet Problem #4

H.W. Assignment

• Normal Distribution Worksheet #1 and #2 • Be prepared for quiz on 2.4 and 2.5 next class! • Have your notes and warm-ups organized in the notes section of your notebook. You should all 10 terms copied and defined for 2.4 and 2.5 in your definition section in your notebook. 10 pts for terms (1pt each) from recentering to standard unit z-score; 15 pts for each of the notes(10pts) with warm-up (5pts) 6x 15pts = 90 pts for Notes