Exam 8: Continuous Probability Distributions

NARRBEGIN: Subway Waiting Time Subway Waiting Time At a subway station the waiting time for a subway is found to be uniformly distributed between 1 and 5 minutes.NARREND -{Subway Waiting Time Narrative} What is the probability that the subway arrives in the first minute and a half?

P(Z < 3.00) is approximately ____________________.

Lamont took a psychology exam whose mean was 70 with standard deviation 5. He also took a calculus exam whose mean was 80 with standard deviation 10. He scored 85 on both exams. On which exam did he do better compared to the other students who took the exam?

NARRBEGIN: Counter Sales Counter Sales Suppose that customers arrive at a counter at an average rate of three customers per minute and that their arrivals follow the Poisson model.NARREND -{Counter Sales Narrative} Write the probability density function of the distribution of the time that will elapse before the next customer arrives.

NARRBEGIN: IT Graduates Salary IT Graduates Salary The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500.NARREND -{IT Graduates Salary Narrative} What is the probability of a new graduate getting a starting salary in excess of $55,000?

NARRBEGIN: IT Graduates Salary IT Graduates Salary The recent average starting salary for new college graduates in IT systems is $47,500. Assume salaries are normally distributed with a standard deviation of $4,500.NARREND -{IT Graduates Salary Narrative} What percent of starting salaries are no more than $42,250?

As the degrees of freedom approach infinity, the values of a Student t distribution approach those of a standard normal distribution.

The probability density function of a uniform random variable on the interval [0, 5] must be ____________________ for 0 $\le$ 0 x $\le$ 5.

The sum of all values of f(x) over the range of [a, b] must equal one.

Which of the following statements is correct regarding the percentile points of the F distribution?

A(n) ____________________ random variable has a density function that looks like a rectangle and you can use areas of a rectangle to find probabilities for it.

Which of the following is not a characteristic for a normal distribution?

The mean and standard deviation of an exponential random variable are equal to each other.

What number corresponds to t_0.05,10?

The total area under f(x) for a continuous random variable must equal ____________________.