Answer:
number 4 i gess
Step-by-step explanation:
A^-b is the same as 1/a^b.
When there is a negative power, place the number and power over 1.
a^b/a^c = a^(b-c).
c is a negative power, because it is being divided, and is underneath b, which is a positive (and so it stays in the numerator).
a^c/b^c = (a/b)^c
Inside this one, the power of c is distributed to all numbers inside the parenthesis, in this case a and b.
hope this helps
Answer:
0.8041 = 80.41% probability that a given battery will last between 2.3 and 3.6 years
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
A certain type of storage battery lasts, on average, 3.0 years with a standard deviation of 0.5 year
This means that 
What is the probability that a given battery will last between 2.3 and 3.6 years?
This is the p-value of Z when X = 3.6 subtracted by the p-value of Z when X = 2.3. So
X = 3.6



has a p-value of 0.8849
X = 2.3



has a p-value of 0.0808
0.8849 - 0.0808 = 0.8041
0.8041 = 80.41% probability that a given battery will last between 2.3 and 3.6 years