4.10 find the sd. cholesterol levels for women aged 20 to 34 follow an approximately normal distribution with mean 185 milligrams per deciliter (mg/dl). women with cholesterol levels above 220 mg/dl are con- sidered to have high cholesterol and about 18.5% of women fall into this category. what is the standard deviation of the distribution of cholesterol levels for women aged 20 to 34?

Standard deviation = 38.89 ≈ 39 mg/dl

Step-by-step explanation:

Data provided in the question:

Mean of the normal distribution = 185 milligrams per deciliter

Let X denote the cholesterol level of women aged 20 to 34 (in mg/dl)

Therefore,

P( X > 220 ) = 18.5% = 0.185

Now,

P( X > 220 ) =

Now,

From the standard Z table = 0.185

we have Z = 0.90

Thus,

= 0.90

or

= 0.90

or

Standard deviation =

or

Standard deviation = 38.89 ≈ 39 mg/dl

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40