Statistics and Probability Competency Assessment

What is the population mean of

X={15,25,35,45,55}

• 35

• 30

• 40

• 25

Tags

CCSS.HSS.CP.A.1

CCSS.HSS.CP.A.2

CCSS.HSS.CP.B.8

CCSS.HSS.CP.B.9

Tags

CCSS.HSS.CP.B.9

Sybil took two science tests. The probability of her passing both tests is 0.6 and the probability of her passing the first test is 0.8. What is the probability of her passing the second test if she passed the first test?

• 65% chance of passing the second test

• 75% chance of passing the second test

• 85% chance of passing the second test

• 95% chance of passing the second test

Thomas is conducting an experiment to determine the probability of drawing a purple marble out of the bag. He randomly selects a marble 20 times, and replaces the marble after each selection. His results are listed below.
Red: 4
Green: 6
Blue: 3
Purple: 7

A bag contains 20 marbles. 12 marbles are red, and 8 marbles are green. The marbles are not replaced after they are selected from the bag. What is the probability of selecting a red marble, and then a green marble?

Desmond is planning a vacation for his family. He wants to surprise his family by selecting two vacation activities at random. Desmond writes six vacation activities onto small identical slips of paper and then places the slips of paper into a bag. The vacation activities include skydiving, beach day, art museum, aquarium, sailing tour, and horseback riding.

Desmond’s daughter selects two activities from the bag (without replacing the slip of paper back into the bag). What is the probability of Desmond’s family going skydiving and then visiting the art museum?

• 3%

• 0.32%

• 32%

• 3.2%

Which statement is true?

• When a data distribution skews right, the value of the mean is higher than the value of the median.

• When a data distribution skews right, the value of the mean is lower than the value of the median

• When a data distribution skews left, the value of the mean is higher than the value of the median.

• When a data distribution skews left, the value of the mean is equal to the value of the median.

Will and Christina surveyed their classmates to find out how many pets each person had. They recorded and ordered their data, which is shown below. When the data is graphed, Will thinks it will skew right. Christina thinks the data will skew left. Who is correct, and why?

Over the past four weeks, Deb’s Florist has sold 29, 40, 33, and 36 bouquets each week, respectively. Calculate the standard deviation for this data set. (Hint: start by computing the average, then squaring the difference between each data point and the average. Find the variance by computing the mean of these values, and then take the square root to get the standard deviation.)