Probability and Stats

• 6

• 2

• 5

• 3

Tags

CCSS.6.SP.B.4

CCSS.HSS.ID.A.1

The height of a certain type of geese is normally distributed with a standard deviation of 5 cm. If the probability of randomly choosing a goose that is less than 15 cm tall is 0.102, find the mean of the population.

• 21.35

• 17.23

• 23.45

• 7.35

Tags

CCSS.HSS.ID.A.4

The weight of a large group of moose is normally distributed with a mean of 550kg. If the probability of randomly choosing a moose that weighs less than or equal to 380kg is 0.0146, what is the standard deviation for this population?

• $\approx65$

• $\approx78$

• $\approx47$

• $\approx74$

In a class of 30 IB students, 20 study mathematics SL, 12 study physics and 8 study both of these subjects.

Find the probability that a randomly selected student studies mathematics SL, given that he studies physics.

• $\frac{2}{5}$

• $\frac{3}{5}$

• $\frac{2}{3}$

• $\frac{1}{3}$

Tags

CCSS.HSS.CP.B.6

Consider the events A and B such that P(A∩B)=0.23,

P⁡(A∩B)=0.23, P(A∪B)=0.88 and P⁡(B)=0.59.

Find P(B|A′). Give an exact answer as a decimal or a fraction in fully simplified form.

• 0.7

• 0.75

• 0.68

• 0.65

Tags

CCSS.HSS.CP.B.6

We have two boxes. The first box has 4 yellow and 3 purple marbles. The second box has 3 yellow and 2 purple marbles.

We throw a fair six sided dice and if we get a 1 or 2, we randomly pick a marble from the first box. Otherwise, we randomly pick a marble from the second box.

Given that the marble we picked is yellow, what is the probability that it came from the first box?

Give an exact answer as a fraction in fully simplified form.

• $\frac{15}{62}$

• $\frac{5}{31}$

• $\frac{21}{62}$

• $\frac{10}{31}$

Tags

CCSS.HSS.CP.B.6