Answer:
pretty sure its 9 : 4
Step-by-step explanation:
It does match-
The Y-Intercept is 12
And the slope is -3/1
You can confirm this by counting rise over run in the graph
Starting at the Y-Intercept (Y=12) the graph goes down 3 units (-3) over 1 unit (1)
This confirms that the slope is -3/1
Use a calculator................
The mean = 2,000
s = Sigma ( standard deviation ) = 300
M - 2 s = 2,000- 2 * 300 = 2,000 - 600 = 1,400
M + 2 s = 2,000 + 2 * 300 = 2,000 + 600 = 2,600
Answer.
Useful life of light bulbs within 2 standard deviations of the mean is:
A ) Between 1,400 and 2,600 hours
Isolate the variable by dividing each side by factors that don’t contain the variable.
X = -2
Hope this helps!
Have a great day!