Mary wrote a book of 1536 pages. She numbered all pages by hand. How many times did she write the digit 6?

Response:

vffnxntbdnr Gn fvbbvxgngdfg

Answer:

1. 3.767

2. 0.145

Step-by-step explanation:

Define X as the exam scores and Y as the number of drinks.

X     Y   X-Xbar    Y-Ybar   (X-Xbar)(Y-Ybar)    (X-Xbar)²       (Y-Ybar)²    

75    5    -2.3          2.3          -5.29                      5.29              5.29

92    3     14.7         0.3           4.41                       216.09           0.09

84    2     6.7         -0.7           -4.69                     44.89             0.49

64    4     -13.3        1.3           -17.29                     176.89           1.69

64    2     -13.3       -0.7           9.31                       176.89           0.49

86    7     8.7           4.3           37.41                     75.69            18.49

81     3     3.7           0.3           1.11                         13.69             0.09

61     0    -16.3        -2.7           44.01                     265.69          7.29

73    1      -4.3         -1.7            7.31                        18.49             2.89

93    0    15.7         -2.7           -42.39                    246.49          7.29

sumx=773, sumy=27, sum(x-xbar)(y-ybar)= 33.9, sum(X-Xbar)²= 1240.1,sum(Y-Ybar)²= 44.1

Xbar=sumx/n=773/10=77.3

Ybar=sumy/n=27/10=2.7

1.

Cov(x,y)=33.9/9

Cov(x,y)=3.76667

Thus, the sample covariance of exam scores and energy drink consumption is 3.767

2.

Cor(x,y)=r=33.9/233.85553

Cor(x,y)=r=0.14496

The sample correlation coefficient for the relationship between exam scores and energy drink consumption is 0.145.