Answer:
d. The variance is 9.56 and the standard deviation is 3.09.
Step-by-step explanation:
From the above question, we are given the following data set.
3, 7, 8, 8, 8, 9, 10, 10, 13, 14
a) Mean = 3 + 7 + 8 + 8 + 8 + 9 + 10 + 10 + 13 + 14/ 10
= 90/10
= 9
b) Variance
The formula for sample Variance = (Mean - x)²/ n - 1
Mean = 9
n = 10
Sample Variance =
(3 - 9)² + (7 - 9)² + (8 - 9)² + (8 - 9)² + (8 - 9)² + (9 - 9)² + (10 - 9)² + (10 - 9)² + (13 - 9)² + (14 - 9)² / 10 - 1
= 36 + 4 + 1 + 1 + 1 + 0 + 1 + 1 + 16 + 25/9
= 86/9
= 9.555555556
≈ Approximately 9.56
Variance = 9.56
Sample Standard deviation = √Sample Variance
= √9.56
= 3.0919249667
≈ Approximately 3.09
Answer:
the decimal is 0.44 repeated
Answer:
- baseball: 5 ounces
- basketball: 20 ounces
Step-by-step explanation:
Let "e" represent the weight of a baseball, and "k" represent the weight of a basketball, all weights being in ounces. Then the given information can be summarized as ...
8e +2k = 80
5e +3k = 85
We can divide the first equation by 2 and subtract 4e to get ...
k = 40 -4e
This can be substituted into the second equation to give ...
5e +3(40 -4e) = 85
-7e +120 = 85 . . . . . . . simplify
35 = 7e . . . . . . . . . . . . add 7e-85
5 = e . . . . . . . . . . . . . . divide by 7
k = 40 -4·5 = 20 . . . . . find k using the above equation
The weight of a baseball is 5 ounces; a basketball, 20 ounces.