MATH 1280 UPDATED ACTUAL Questions and CORRECT Answers

MATH 1280 UPDATED ACTUAL
Questions and CORRECT Answers
You are interested in the number of English-speaking people on the planet who want
to play a new kind of online video game. You asked 300 college students if they were
interested in playing video games, 100 said yes, and of them 20 preferred your game
to an existing game that is widely used.
How many people were in the sample?


a. The number of English-speaking people on the planet who want to play a new kind of
online video game.
b. 300
c. 200
d. 100

e. 2 - CORRECT ANSWER - b. 300


What is the mean of x?
x <- c(12, 14, 11, 14, 13, 15, 12, 16, 10)


Select one:
a. 12
b. 13
c. 14
d. 15

e. 16 - CORRECT ANSWER - b. 13


Using the value of x from the prior question, what is the standard deviation of x?

, Select one:
a. 1
b. 3.75
c. 9
d. sqrt(13)

e. 1.94 - CORRECT ANSWER - e. 1.94


There was a very short quiz with ve questions. The following table shows the
number of correct answers and the cumulative relative frequency for those scores in
the class.
value: 2 3 4 5
cumulative
relative
frequency:
.13 .55 .925 1
What is the probability that a randomly selected student from the class scored a 3 on
the short quiz?


Select one:
a. .13
b. .42
c. .55
d. .375

e. .925 - CORRECT ANSWER - b. .42


Use this information for the next three questions.
A random variable called L is dened by the following table, but one of the relative
frequencies is missing: