Module 2 Exercise 2

Let the normal random variable X be the weight in lbs. of a green batch student. In this distribution, approximately 99.7% of the weights fall within 104 and 152 lbs.

What is the mean of this distribution? (Indicate the value ONLY. Do not label)

Let the normal random variable X be the weight in lbs. of a green batch student. In this distribution, approximately 99.7% of the weights fall within 104 and 152 lbs.

What is the standard deviation of this distribution? (Indicate the value ONLY. Do not label)

Let the normal random variable X be the weight in lbs. of a green batch student. In this distribution, approximately 99.7% of the weights fall within 104 and 152 lbs.

In which TWO values will approximately 68% of the weights fall?

• 120

• 136

• 112

• 144

Let the normal random variable X be the weight in lbs. of a green batch student. In this distribution, approximately 99.7% of the weights fall within 104 and 152 lbs.

Approximately what percent of the batch would you expect to weigh greater than 144 lbs?

• 2.5%

• 2.35%

• 13.5%

• 15.85%

Let the normal random variable X be the weight in lbs. of a green batch student. In this distribution, approximately 99.7% of the weights fall within 104 and 152 lbs.

What is the probability that a student weighs less than 112 lbs?

• 2.35%

• 2.5%

• 13.5%

• 15.85%

The time spent by kids in front of the television can be modelled by a normal distribution. In this distribution, about 95% of the kids spend between 1000 and 2000 hours in front of the television.

What is the mean of this distribution? (Indicate the value ONLY. Do not label.)

The time spent by kids in front of the television can be modelled by a normal distribution. In this distribution, about 95% of the kids spend between 1000 and 2000 hours in front of the television.

What is the standard deviation of this distribution? (Indicate the value ONLY. Do not label.)

The time spent by kids in front of the television can be modelled by a normal distribution. In this distribution, about 95% of the kids spend between 1000 and 2000 hours in front of the television.

In which TWO values will about 68% of the TV time fall?

• 1250

• 1750

• 750

• 2000

The time spent by kids in front of the television can be modelled by a normal distribution. In this distribution, about 95% of the kids spend between 1000 and 2000 hours in front of the television.

What is the probability that a kid spends between 1250 and 2000 hours in front of the television?

• 0.815

• 0.68

• 0.34

• 0.7035

The time spent by kids in front of the television can be modelled by a normal distribution. In this distribution, about 95% of the kids spend between 1000 and 2000 hours in front of the television.

What is P(X < 2250)?

• 0.9985

• 0.0015

• 0.9765

• 0.8415