High Fructose Corn Syrup (HFCS) is a sweetener in food products that is linked to obesity and type II diabetes. The mean annual consumption in the United States in 2008 of HFCS was 60 lbs with a standard deviation of 20 lbs. Assume the population follows a Normal Distribution. a. Find the probability a randomly selected American consumes more than 50 lbs of HFCS per year.
b. Find the probability a randomly selected American consumes between 30 and 90 lbs of HFCS per year.
c. Find the 80th percentile of annual consumption of HFCS.
d. In a sample of 40 Americans how many would you expect to consume more than 50 pounds of HFCS per year.
e. Between what two numbers would you expect to contain 95% of Americans HFCS annual consumption?
f. Find the quartile and Interquartile range for this population.
g. A teenager who loves soda consumes 105 lbs of HFCS per year. Is this result unusual?

Explained below.

Step-by-step explanation:

X = annual consumption in the United States in 2008 of HFCS

(a)

Find the probability a randomly selected American consumes more than 50 lbs of HFCS per year.

P (X > 50) = 0.6915.

(b)

Find the probability a randomly selected American consumes between 30 and 90 lbs of HFCS per year.

P (30 < X < 90) = 0.8664.

(c)

Find the 80th percentile of annual consumption of HFCS.

P (X < x) = 0.80

⇒ P (Z < z) = 0.80

⇒ z = 0.84

80th percentile = 76.8.

(d)

In a sample of 40 Americans how many would you expect to consume more than 50 pounds of HFCS per year.

P (X > 50) = 0.6915

Number of American who consume more than 50 lbs = 40 × 0.6915

                                                                                          = 27.66

                                                                                          ≈ 28

Expected number = 28.

(e)

Between what two numbers would you expect to contain 95% of Americans HFCS annual consumption?

According to the Empirical rule, 95% of the normally distributed data lies within 2 standard deviations of mean.

Range = 20 < X < 100.

(f)

Find the quartile and Interquartile range for this population.

1st quartile: Q₁

P (X < Q₁) = 0.25

⇒ P (Z < z) = 0.25

⇒ z = -0.67

3rd quartile: Q₃

P (X < Q₃) = 0.75

⇒ P (Z < z) = 0.75

⇒ z = 0.67

Inter quartile range:

(g)

Compute the z-score for x = 105 lbs as follows:

Z-scores greater than +2.00 or less than -2.00 are considered as unusual.

Thus, the result unusual.

boxplot e is the answer