Answer: C.-1.5
Step-by-step explanation:
Given: The burning time of a very large candle is normally distributed with mean
of 2500 hours and standard deviation
of 20 hours.
Let X be a random variable that represent the burning time of a very large candle.
Formula: 
For X = 2470

So, the z-score they corresponds to a lifespan of 2470 hours. =-1.5
Hence, the correct option is C.-1.5.
Answer:
x = 40/3
Step-by-step explanation:
2/3 = (8/x) + 6
-6 -6
2/3 - 6 = -16/3
-16/3 = 8/x
*x *x
(-16/3)x = 8
+16/3 +16/3
x = 40/3
Answer: 0.1824
Step-by-step explanation:
Given : The mileage per day is distributed normally with
Mean : 
Standard deviation : 
Let X be the random variable that represents the distance traveled by truck in one day .
Now, calculate the z-score :-

For x= 132 miles per day.

For x= 159 miles per day.

Now by using standard normal distribution table, the probability that a truck drives between 132 and 159 miles in a day will be :-

Hence, the probability that a truck drives between 132 and 159 miles in a day =0.1824
Answer:
The subtraction property of equality
Option A is correct
Explanation:
The given equation is:
12 - x = 7x + 32
Subtract 12 from both sides
12 - 12 - x = 7x + 32 - 12
-x = 7x + 20 (Step 1)
From step 1 above, subtract 7x from both sides
-x - 7x = 7x - 7x + 20
-8x = 20 (Step 2)
Since we subtracted 7x from both sides to get step 2, the justification for step 2 is the subtraction property of equality
Answer:
X=15
Step-by-step explanation: