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p/ledge.apus.edu/portal/site/309110/page/1d70d746-8716-478a-bc7c-4950149odd31 Qu

ID: 3155275 • Letter: P

Question

p/ledge.apus.edu/portal/site/309110/page/1d70d746-8716-478a-bc7c-4950149odd31 Question 18 of 20 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign idcators EMes (e g, as or "e" (used in scientific notation). NOTE: For scientific Complex numbers should be in the form la + bi where "at and "o need to have exdlicity stated vaues For example: {1+1) is valid whereas {1+i) is not {0 is vaid whereas (9) is not al point markers (period or comma), sign indicators (-, spaces (e.g. as thousands separator, 5 000), 'E notation, a period MUST be used as the decimal point marker S ) a not (o-9lI vaild wr The tollowing data represent the number of children in a sampe of 10 tamiles tom Chica 42. 1.1.5.3.0. 1.0 and 2 ot 10 families trom Chicago: 4, 2, 1. 1,5.3,0. 1,0, and 2 Compute the variance of the data. Place your answer, rounded to two decimal places, in the blank For example, 3.45 would be a legitimate entry to two dencimal placen. I nhe blank Ffor exampose.3.45 would bo a segtinas Part 3 of 3- 1.0 Points Question 19 of 20 If we draw a straight line through the points in a scat relationship between the two variables. True False 1.0 Points but a tew pui down the clas averege,the hintogram cdesemting th to Question 20 of 20 If you are in a class where most students do reasonably well on a test but a few pull down the class do roasonably well on a test but a tew pull down the class average, the histogram desaribing the teset scores will indicate a positively-skewed distribution. True False

Explanation / Answer

18.

Getting the mean, X,          
          
X = Sum(x) / n          
Summing the items, Sum(x) =    19      
As n =    10      
Thus,          
X =    1.9      
          
Setting up tables,          
x   x - X   (x - X)^2  
4   2.1   4.41  
2   0.1   0.01  
1   -0.9   0.81  
1   -0.9   0.81  
5   3.1   9.61  
3   1.1   1.21  
0   -1.9   3.61  
1   -0.9   0.81  
0   -1.9   3.61  
2   0.1   0.01  
          
Thus, Sum(x - X)^2 =    24.9      
          
Thus, as           
          
s^2 = Sum(x - X)^2 / (n - 1)          
          
As n =    10      
          
s^2 =    2.766666667 = 2.77 [ANSWER, VARIANCE]      


19.

TRUE. [ANSWER]

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20.

FALSE. [ANSWER]

There are a few low scores, so it is negatively skewed.