# QNT 275 Week 3 Quiz

**https://uopcourses.com/category/qnt-275/**

**Week 3 Quiz**

**•**

**question1**

**What does it**

mean when we say that the tails of the normal curve are asymptotic to the x

axis?

mean when we say that the tails of the normal curve are asymptotic to the x

axis?

**o**

**The tails gets**

closer and closer to the x axis and eventually touch it.

closer and closer to the x axis and eventually touch it.

**o**

**The tails get**

closer and closer to the x axis and eventually cross this axis.

closer and closer to the x axis and eventually cross this axis.

**o**

**The tails get**

closer and closer to the x axis but never touch it.

closer and closer to the x axis but never touch it.

**o**

**The tails get**

closer and closer to the x axis and eventually become this axis.

closer and closer to the x axis and eventually become this axis.

**question2**

**You work in**

marketing for a company that produces work boots. Quality control has sent you

a memo detailing the length of time before the boots wear out under heavy use.

They find that the boots wear out in an average of 208 days, but the exact

amount of time varies, following a normal distribution with a standard

deviation of 14 days. For an upcoming ad campaign, you need to know the percent

of the pairs that last longer than six months-that is, 180 days. Use the

empirical rule to approximate this percent.

marketing for a company that produces work boots. Quality control has sent you

a memo detailing the length of time before the boots wear out under heavy use.

They find that the boots wear out in an average of 208 days, but the exact

amount of time varies, following a normal distribution with a standard

deviation of 14 days. For an upcoming ad campaign, you need to know the percent

of the pairs that last longer than six months-that is, 180 days. Use the

empirical rule to approximate this percent.

**o**

**95%**

**o**

**2.5%**

**o**

**97.5%**

**o**

**5%**

**•**

**•**

**question3**

**For any normally**

distributed random variable with mean μ and standard deviation σ, the percent

of the observations that fall between

and is closest to _______.

distributed random variable with mean μ and standard deviation σ, the percent

of the observations that fall between

and is closest to _______.

**o**

**95%**

**o**

**16%**

**o**

**68%**

**o**

**32%**

**•**

**•**

**question4**

**A continuous**

random variable has the uniform distribution on the interval [a, b] if its

probability density functionf(x) ___________.

random variable has the uniform distribution on the interval [a, b] if its

probability density functionf(x) ___________.

**o**

**is constant for**

all x between a and b, and 0 otherwise

all x between a and b, and 0 otherwise

**o**

**is bell-shaped**

between a and b

between a and b

**o**

**is symmetric**

around its mean

around its mean

**o**

**asymptotically**

approaches the x axis when x increases to +

approaches the x axis when x increases to +

**∞**

**or decreases to -**

**∞**

**•**

**•**

**•**

**question5**

**Mutually**

exclusive and collectively exhaustive events _______________.

exclusive and collectively exhaustive events _______________.

**o**

**do not have to**

contain all outcomes in a sample space and may share common outcomes

contain all outcomes in a sample space and may share common outcomes

**o**

**contain all**

outcomes in a sample space and do not share common outcomes.

outcomes in a sample space and do not share common outcomes.

**o**

**contain all**

outcomes in a sample space and may share common outcomes

outcomes in a sample space and may share common outcomes

**o**

**do not have to**

contain all outcomes in a sample space but do not share common outcomes

contain all outcomes in a sample space but do not share common outcomes

**•**

**•**

**•**

**•**

**question6**

**What is**

probability?

probability?

**o**

**Any value**

between 0 and 1 is always treated as a probability of an event.

between 0 and 1 is always treated as a probability of an event.

**o**

**A value between**

0 and 1 assigned to an event that measures the likelihood of its occurrence.

0 and 1 assigned to an event that measures the likelihood of its occurrence.

**o**

**A value between**

0 and 1 assigned to an event that measures the unlikelihood of its occurrence.

0 and 1 assigned to an event that measures the unlikelihood of its occurrence.

**o**

**A numerical**

value assigned to an event that measures the number of its occurrences.

value assigned to an event that measures the number of its occurrences.

**•**

**•**

**•**

**question7**

**Which of the**

following can be represented by a continuous random variable?

following can be represented by a continuous random variable?

**o**

**The number of**

arrivals to a drive-thru bank window in a four-hour period

arrivals to a drive-thru bank window in a four-hour period

**o**

**The number of**

defective light bulbs in a sample of 5

defective light bulbs in a sample of 5

**o**

**The score of a**

randomly selected student on a five-question multiple-choice quiz

randomly selected student on a five-question multiple-choice quiz

**o**

**The time of a**

flight between Chicago and New York

flight between Chicago and New York

**•**

**•**

**•**

**•**

**question8**

**Which of the following**

is correct?

is correct?

**o**

**A continuous**

random variable has a probability density function but not a cumulative

distribution function.

random variable has a probability density function but not a cumulative

distribution function.

**o**

**A continuous**

random variable has a probability density function, and a discrete random

variable has a probability mass function.

random variable has a probability density function, and a discrete random

variable has a probability mass function.

**o**

**A discrete**

random variable has a probability mass function but not a cumulative

distribution function.

random variable has a probability mass function but not a cumulative

distribution function.

**o**

**A continuous**

random variable has a probability mass function, and a discrete random variable

has a probability density function.

random variable has a probability mass function, and a discrete random variable

has a probability density function.

**•**

**•**

**•**

**question9**

**Which of the**

following can be represented by a discrete random variable?

following can be represented by a discrete random variable?

**o**

**The finishing**

time of participants in a cross-country meet

time of participants in a cross-country meet

**o**

**The number of**

obtained spots when rolling a six-sided die

obtained spots when rolling a six-sided die

**o**

**The average**

outside temperature taken every day for two weeks

outside temperature taken every day for two weeks

**o**

**The height of**

college students

college students

**•**

**•**

**•**

**•**

**question10**

**The probability**

that a normal random variable is less than its mean is ____.

that a normal random variable is less than its mean is ____.

**o**

**Cannot be**

determined

determined

**o**

**0.0**

**o**

**1.0**

**o**

**0.5**

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