CFA 4 - Probability

Your sock drawer has four white socks,

two brown socks, and four black socks.

You randomly pick two socks and get a

matching pair of black socks.

• 2 / 15 or 0.133

• 1 / 7 or 0.143

• 7 / 26 or 0.269

• 8 / 33 or 0.242

A bag contains five red marbles and seven

blue marbles. You randomly pick a

marble and then return it to the bag before

picking another marble. Both the first and

second marbles are red.

• 8 / 33 or 0.242

• 25 / 169 or 0.148

• 1 / 4 or 0.25

• 21 / 55 or 0.382

The student body of 30 students wants to

elect a president, vice president, secretary,

and treasurer.

• 131,544

• 27,405

• 330,820

• 657,720

The student body of 270 students wants to

elect two representatives.

• 7,263

• 21,710

• 36,315

• 45,676

You are setting the combination on a

four-digit lock. You want to use the

numbers 6241 but don't care what order

they are in.

• 96

• 24

• 12

• 8

Birthweights at a local hospital have a Normal distribution with a mean of 110 oz. and a standard deviation of 15 oz. Which of the following is the proportion of infants with birthweights under 95 oz.?

• 0.16

• 0.025

• 0.34

• 0.5

Birthweights at a local hospital have a Normal distribution with a mean of 110 oz. and a standard deviation of 15 oz. Which of the following is the proportion of infants with birthweights between 125 oz. and 140 oz.?

• 0.135

• 0.27

• 03.475

• 0.68

A worn out bottling machine does not properly apply caps to 5% of the bottles it fills. If you randomly select 20 bottles from those produced by this machine, what is the approximate probability that exactly 2 caps have been improperly applied?

• 0.0002

• 0.19

• 0.74

• 0.81

A worn out bottling machine does not properly apply caps to 5% of the bottles it fills. If you randomly select 20 bottles from those produced by this machine, what is the approximate probability that between 2 and 6 (inclusive) caps have been improperly applied?

• 0.92

• 0.74

• 0.38

• 0.26

Kenny Rogers draws from a bag of marbles. The bag has 12 red, 7 gold, 4 black, and 2 green. What is the probability he will draw a red marble then without replacing draw a black marble?

• 8%

• 64.6%

• 64%

• 9.6%

• 48%