# (Answered) MATH399N week 4 Assignment Discrete Probability

Question

A random sample of high school students were surveyed about technological devices. They were asked, “How many computers do you have in your household?”  The table below represents the probability density function for the random variable X, the number of computers per household. Find the standard deviation of X.

• Round the final answer to two decimal places.
 x P(X = x) 3 1/4 4 1/4 7 1/2

Question

Which of the following tables shows a valid probability density function? Select all correct answers.

Question

Andrew is a quality control inspector at a clothing factory. At the end of each day, he checks the number of imperfections found in cotton sweaters. The table below represents the probability density function for the random variable X, the number of imperfections found in cotton sweaters per day. Find the standard deviation of X.

• Round the final answer to two decimal places.
 x P(X = x) 0 1/6 1 1/6 4 1/3 7 1/3

Question

During a college football national championship, the number of times football teams scored a touchdown was recorded by a scorekeeper every quarter. The table below represents the probability density function for the random variable X, the number of touchdowns per quarter. Find the standard deviation of X.

• Round the final answer to two decimal places.
 x P(X = x) 1 1/5 2 1/5 8 1/5 9 2/5

Question

Which of the following tables shows a valid probability density function? Select all correct answers.

Question

Which of the following tables shows a valid probability density function? Select all correct answers.

Question

A casino features a game in which a weighted coin is tossed several times. The table shows the probability of each payout amount (assume that the remaining probability has a payout of 0 so that the probabilities add to 1). To the nearest dollar, what is expected payout of the game?

 Payout Amount \$130 \$4,400 \$195,000 Probability 0.156 0.023 0.0007

Question

A casino features a game in which a weighted coin is tossed several times. The table shows the probability of each payout amount (assume that the remaining probability has a payout of 0 so that the probabilities add to 1). To the nearest dollar, what is expected payout of the game?

 Payout Amount \$180 \$1,000 \$155,000 Probability 0.151 0.029 0.0007

# Solution:

Question

A random sample of high school students were surveyed about technological devices. They were asked, “How many computers do you have in your household?”  The table below represents the probability density function for the random variable X, the number of computers per household. Find the standard deviation of X.

• Round the final answer to two decimal places.
 x P(X = x) 3 1/4 4 1/4 7 1/2 