Question

1. The temperature in degrees Fahrenheit and the number of emergency calls are shown below. Determine if there is a relationship between the temperature and the number of emergency calls received. Use .05 significance.

Number of Calls (Y)	Temperature (X)
7	68
4	74
8	82
10	88
11	93
9	99
13	101

What is the value of the Coefficient of Determination (R2)?

Select one:

a. .5899.

b. .6583.

c. .8114.

d. .2577.

2. The average chocolate chip cookie contains 110 calories. A random sample of 15 different brands of chocolate chip cookies found that the average amount of calories was 127 calories with a sample standard deviation of 6.23 calories. At .01 level of significance, test the hypothesis that the average calories for chocolate chip cookies is greater than 110.

What are your null (H0) and alternative (H1) hypotheses?

Select one:

a. H0: The mean is equal to 127.
H1: The mean is not equal to 127.

b. H0: The mean is greater than 110.
H1: The mean is not greater than 110.

c. H0: The mean is equal to 110.
H1: The mean is greater than 110.

d. H0: The mean is equal to 127.
H1: The mean is greater than 127.

Answer 1

1)

X	Y	x^2	y^2	xy
68	7	4624	49	476
74	4	5476	16	296
82	8	6724	64	656
88	10	7744	100	880
93	11	8649	121	1023
99	9	9801	81	891
101	13	10201	169	1313

sum x	sum y	sum x^2	sum y^2	sum xy	n
605.0000	62.0000	53219.0000	600.0000	5535.0000	7.0000

corr coef, r =
{n*sum(XY) - sum(X)*sum(Y)} / { sqrt(n*sum(x^2)-[sum(x)]^2) * sqrt(n*sum(y^2)-[sum(y)]^2) }
{7*5535-605*62} / { sqrt(7*53219-[605]^2) * sqrt(7*600-[62]^2) }
0.8114

coef of determination, R^2
0.8114^2
0.65836996

b. .6583

2)

c. H0: The mean is equal to 110.
H1: The mean is greater than 110.