Exam 5: Continuous Random Variables

The fuel efficiency rating for a mid-size car is normally distributed with a mean of 32 and a standard deviation of 0.8. What is the probability that the rating for a selected mid-size car would be: -More than 33.2?

Is between 2 and 4 minutes?

The mean and median are the same for a normal distribution.

The number of defective pencils in a lot of 1000 pencils can be modeled using a continuous probability distribution.

A continuous probability distribution having a rectangular shape where the probability is evenly distributed over an interval of numbers is called a uniform probability distribution.

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. -What percentage of students scored between 81 and 89?

The exponential probability distribution is used to model a continuous random variable.

The weight of a product is normally distributed with a mean of four grams and a variance of .25 "squared grams." What is the probability that a randomly selected unit from a recently manufactured batch weighs: -More than 5 grams?

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20. What percentage of the time will the number of boxes received weekly be -Greater than 200

The average time a subscriber spends reading the local newspaper is 49 minutes. Assume the standard deviation is 16 minutes and that the times are normally distributed. -What is the probability a subscriber will spend at least 1 hour reading the paper?

The price of an energy sports drink is normally distributed with an average of $2.25 and a standard deviation of $0.15 across store outlets. -What price will 77% of the drink prices fall above?

A property of continuous probability distributions is that:

Consider a normal population with a mean of 10 and a standard deviation 2. -Find P(X = 10).

If a personnel aptitude test score of 32 has a z-score of 1.2,and a score of 24 has a z-score of -.4,what is the mean test score of the distribution?

Let X be a binomial random variable with n = 150 and p = 0.3.Approximate P(X $\geq$ 50))

A manufacturer of personal computers sets tests competing brands and finds that the amounts of energy they require are normally distributed with a mean of 285 kwh and a standard deviation of 9.1 kwh. If the lowest 25% and the highest 30% are not included in a second round of tests,what are the upper and lower limits for the energy amounts of the remaining sets?

Consider a normal population with a mean of 10 and a standard deviation 2. -Find P(X > 7).

The weight of a product is normally distributed with a mean of four grams and a variance of .25 "squared grams." What is the probability that a randomly selected unit from a recently manufactured batch weighs: -No more than 3.5 grams?

The normal approximation of the binomial distribution is appropriate when:

The flying time of a drone airplane has a normal distribution with mean 4.76 hours and standard deviation of .04 hours. What is the probability that the drone will fly: -Between 4.70 and 4.82 hours?