AP STAT- Ch. 4 and Ch. 5 practice

1)Use the following data: {5, 7, 8, 10, 12, 15, 17, 20, 30, 31, 22, 25, 28, 33, 34, 35, 39, 40} (list Ques1)

  1. Find the Mean, Median, Range, IQR, and Standard deviation.

Mean = 22.833

Median = 23.5

Range = (5, 40)

IQR = 21

Std. Dev = 11.521

  1. Create a boxplot of the data

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512 23.5 33 40

Question 1 data

  1. Suppose we add the data point 62 to this set of data. Indicate how each of the statistics in part (a) would change: increase, decrease, or stay about the same.

Mean = Increase

Median = About the same

Range = Increase

IQR = About the same

Std. Dev = Increase

2)The following are quiz scores from two Algebra 1 Classes.

Class 1: {68, 93, 53, 100, 77, 86, 91, 88, 72, 74, 66, 82}and Class 2: {77, 91, 82, 68, 75, 72, 85, 65, 70, 79, 94, 86}

  1. Compare the means of the class scores. Which would you rather be in?

Mean of Class 1 = 79.167

Mean of Class 2 = 78.667

I would rather be in Class 1- they have the higher mean

  1. Compare the standard deviations. Which class was more consistent in their scores?

Std. Dev. of Class 1 = 13.361

Std. Dev. of Class 2 = 9.188

Class 2 had the more consistent scores. I would now rather be in class 2 because their mean was not that much lower and they were more consistent. Class 1 was more spread out.

3)Based solely on the mean and median given, decide on the shape of the distribution, and what measure of center and spread you would report.

(a)Mean = 100(b) Mean = 20(c) Mean = 934

Median = 98Median = 41Median = 850

SYMMETRICLEFT SKEWRIGHT SKEW

Mean and Std. Dev.Median, IQRMedian, IQR

4)Use the following set of data:

{3, 4, 4, 4, 5, 6, 6, 7, 8, 10, 11, 11, 16, 17, 20, 25, 28, 30, 31, 39, 45, 59, 68, 73} (list Ques4)

  1. Look at (not draw) a histogram of the data (just use Zoom 9, no need to adjust the window).
  1. Describe the distribution (be sure to use the correct measure of center and spread)

Shape: Right skewed, unimodal

Center: Median of 13.5 units

Spread: IQR of 24.5 units, Range of (3, 73) units

  1. Are there any outliers present? Justify your answer.

IQR = 24.51.5 * IQR = 36.75

LF = Q1 – 36.75 = -30.75

UF = Q3 + 36.75 = 67.25

Anything outside of (-30.75, 67.25) is considered an outlier. Therefore, there are 2 outliers: 68 and 73.

5)Give a set of numbers that would have a standard deviation of 0

Any set of data where all numbers are the same. For example: {10, 10, 10, 10, 10, 10, 10}

6)The Presidents of the USA and their Age of Death (list PRES). Create a Relative Frequency Histogram and describe the distribution.

45 50 55 60 65 90 95

Presidents Ages of Death

Description:Right skewed, unimodal. Center at the Median of 67 years. Spread is an IQR of 18 years, and a range of (46, 93) years.