Answer:
Step-by-step explanation:
<u>3 hours for studying x subjects:</u>
D. 171
-
Explanation:
4(2+5)^2 - 5^2
4 x 7^2 - 5^2
4 x 49 - 25
196 - 25
171
Answer: D. 171
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
50 ≥ 20 + 6x
She can spend less than 50 or 50 dollars exactly. 20 represents the amount for the jeans. The x represents the t-shirts. 6 represents cost per t-shirt.
