11-5 Test - Unit 4 Discrete Probability Distributions

Determine whether this statement represents a discrete or a continuous random variable.

The cost of a notebook.

• Discrete

• Continuous

Determine whether this statement represents a discrete or a continuous random variable.

The weight of a football.

• Discrete

• Continuous

Determine the probability distribution's missing value.

P(x) = 0.2, 0.34, 0.12, 0.26, ?

• 1

• 0.800

• 0.080

• 0.085

At a raffle, 5000 tickets are sold at $4 each. One ticket will be randomly selected and the winner will receive an iphone valued at $ 760. What is the expected value for a person that buys one ticket?

• -$3.58

• -$3.85

• -$3.68

• -$3. 86

At a raffle, 1200 tickets are sold at $10 each for three prizes valued at $1800, $1500, and $1200. What is the expected value of one ticket?

• -$6.35

• -$6.55

• -$6.25

• -$6.65

A recent survey found out that 75% of teenagers wear glasses. In a random sample of 15 teenagers, what is the probability that exactly 10 of them wear glasses? (Binomial)

• 0.1651

• 0.3135

• 0.0486

• 0.0645

Based on statistics test result, 81% of students pass the test. Find the probability that 22 of 30 students pass the test. (Binomial)

• 0.0651

• 0.0964

• 0.0486

• 0.0336

A recent survey found out that 76% of all teenagers over 13 play video games. In a random sample of 120 teenagers over 13, what is the mean and standard deviation of those who play games?

• $\mu=91.40,\ \ \ \sigma=4.86$

• $\mu=91.20,\ \ \ \sigma\ =\ 4.68$

• $\mu=91.20,\ \ \ \sigma\ =\ 21.89$

• $\mu=-9.20,\ \ \ \sigma=\ 21.89$

The probability that a tennis set will go to a tiebreaker is 23%. In 156 randomly selected tennis sets, what is the mean and standard deviation of the number of tiebreakers?  $Hint:\ \mu=np,\ \ \sigma\ =\ \sqrt{npq}$  

•  $\mu=35.88,\ \ \ \sigma=\ 5.26$  

•  $\mu=\ 35.88,\ \ \sigma\ =\ 27.63$  

•  $\mu=27.63,\ \sigma\ =\ 5.26$  

•  $\mu=27.63,\ \ \sigma=\ 35.88$  

A amateur baseball player makes a bat at 78% of the time. Find the probability that he misses his first 2 bats and makes it on the 3th bat. Round your answer to four decimal places. (Geometric)

• 0.0389

• 0.0378

• 0.0342

• 0.0345