AP Stats Quiz 6.1 & 6.2

A vending machine operator has determined that the number of candy bars sold per week by a certain machine is a random variable with mean 125 and standard deviation 7. His profit on each bar sold is $0.25, and it costs him $5.00 per week to maintain the machine and rent the space for it. What are the mean and standard deviation for Y = the profit he earns from this machine in a randomly-selected week?

• Mean = 31.25, Standard deviation –$3.25

• Mean = 31.25, Standard deviation $1.25

• Mean = 31.25, Standard deviation $1.75

• Mean = 26.25, Standard deviation $1.25

• Mean = 26.25, Standard deviation $1.75

A rock concert producer has scheduled an outdoor concert. If it is warm that day, she expects to make a $20,000 profit. If it is cool that day, she expects to make a $5000 profit. If it is very cold that day, she expects to suffer a $12,000 loss. Based upon historical records, the weather office has estimated the chances of a warm day to be 0.60; the chances of a cool day to be 0.25. What is the producer’s expected profit?

• $5,000

• $11,450

• $13,000

• $13,250

• $15,050

Tags

CCSS.HSS.MD.A.2

In the town of Tower Hill, the number of cell phones in a household is a random variable W with the shown distribution. The probability that a randomly-selected household has at least two cell phones is

• 0.20

• 0.25

• 0.55

• 0.70

• 0.80

Let the random variable X represent the profit made on a randomly selected day by a certain store. Assume that X is approximately normal with mean $360 and standard deviation $50. What is P(X> $400)?

• 0.2119

• 0.2881

• 0.5319

• 0.7881

• 0.8450

Tags

CCSS.HSS.ID.A.4

Identify whether the experiment involves a discrete or a continuous random variable.

Recording the number of points scored by a NBA team in each game of the 2018 season

• Discrete Random Variable

• Continuous Random Variable

Identify whether the experiment involves a discrete or a continuous random variable.

Measuring the length of time it takes before a dolphin surfaces in the ocean to breath

• Discrete Random Variable

• Continuous Random Variable

Tags

CCSS.6.SP.A.3

Find the probability the snowfall will be between 3 and 6 inches.

• .2
• .4
• .6
• 1

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.4

The mean amount of time to mix the batter for a cake is 14 minutes with a standard deviation of 2.5 minutes. The mean amount of time to bake the cake is 35 minutes with a standard deviation of 6.2 minutes. What is the mean time to make and bake a cake? What is the standard deviation?

• mean = 49 min sd = 8.7 min

• mean = 49 min sd = 6.685 min

• mean = 21 min sd = 8.7 min

• mean = 21 min sd = 6.685 min

A random variable X has a mean of 120 and a standard deviation of 15. A random variable Y has a mean of 100 and a standard deviation of 9. If X and Y are independent, approximately what is the standard deviation of X – Y?

• 24.0

• 17.5

• 12.0

• 6.0

• 4.9

A regular deck of cards has 4 aces. You are asked to pick one card from the deck. If the card you picked is an ace you win $5! However if you pick any other card, you lose $2. If you play this game many times, on average how much would you expect to win?

• About $1.46
• About $4.46
• About -$1.46
• About $3

Tags

CCSS.HSS.MD.B.5A