Answer:
This statement can be made with a level of confidence of 97.72%.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 8.1 mm
Standard Deviation, σ = 0.5 mm
Sample size, n = 100
We are given that the distribution of thickness is a bell shaped distribution that is a normal distribution.
Formula:
Standard error due to sampling:

P(mean thickness is less than 8.2 mm)
P(x < 8.2)
Calculation the value from standard normal z table, we have,

This statement can be made with a level of confidence of 97.72%.
Answer:
17, 18, 19, 20, 21
Step-by-step explanation:
54 is the hypotenuse because it is the longest side. Square all of the sides. So 54^2=2916
51^2=2601
22^2=484
Now you have 2916=2601+484
Add the two and they will be greater than 2916. Because of that, you will have an acute triangle because 22^2+51^2>54^2
In short, its B
Answer:
x=-3
Step-by-step explanation:
(3x-15)/2 = 4x
Multiply each side by 2
(3x-15)/2 *2= 4x*2
3x-15 = 8x
Subtract 3x from each side
3x-15-3x = 8x-3x
-15 = 5x
Divide each side by 5
-15/5 = 5x/5
-3 =x