Complete the mcq:
1.Which of the following is correct?
• A continuous random variable has a probability density function but not a cumulative distribution function.
• A continuous random variable has a probability density function, and a discrete random variable has a probability mass function.
• A discrete random variable has a probability mass function but not a cumulative distribution function.
• A continuous random variable has a probability mass function, and a discrete random variable has a probability density function.
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.
o 5%
o 2.5%
o 97.5%
o 95%
What is probability?
o Any value 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.
o A value between 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.
Mutually exclusive and collectively exhaustive events _______________.
do not have to contain all outcomes in a sample space and may share common outcomes
do not have to contain all outcomes in a sample space but do not share common outcomes
contain all outcomes in a sample space and do not share common outcomes.
contain all outcomes in a sample space and may share common outcomes
The probability that a normal random variable is less than its mean is ____.
Cannot be determined
1.0
0.5
0.0