38. The nearest whole number to 38.49 is 38 because at .5 you begin rounding up to the nearest whole number.
Answer:
1. Rewriting the expression 5.a.b.b.5.c.a.b.5.b using exponents we get: 
5. 
6. 
7. 
Step-by-step explanation:
Question 1:
We need to rewrite the expression using exponents
5.a.b.b.5.c.a.b.5.b
We will first combine the like terms
5.5.5.a.a.b.b.b.b.c
Now, if we have 5.5.5 we can write it in exponent as: 
a.a as
b.b.b.b as: 
So, our result will be:

Rewriting the expression 5.a.b.b.5.c.a.b.5.b using exponents we get: 
Question:
Rewrite using positive exponent:
The rule used here will be:
which states that if we need to make exponent positive, we will take it to the denominator.
Applying thee above rule for getting the answers:
5)
6) 
7) 
We know that
so, we get

The standard deviation of the distribution = 1.5°F
Given that the distribution of daily high temperature is approximately normal.
Population mean,
= 86°F
Also approximately 95% of all daily high temperatures are between 83°F and 89°F.
So here
= 83°F and
= 89°F
We have the z - statistic ,

where
is the Standard deviation.
For 95% probability, the z-value for normal distribution is 1.96.
As we consider the positive z-value, take X =
= 89°F
So, 
⇒
≈ 1.5°F
So the standard deviation of the distribution = 1.5°F
Learn more about standard deviation at brainly.com/question/475676
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x=(13±3√17)/2x
≈ 12.68465843, 0.31534156
Which would be 12.7 and 0.3 If you rounded to the nearest tenth.