Question: The Employee Benefit Research Institute (EBRI) issued a news release ("Saving in America: Three Key Sets of Figures") on October 25, 2005. In 2005, about 69% of workers said they have saved for retirement. The file titled Retirement contains sample data similar to those used in this study.
a. Construct a frequency distribution of the total savings and investments using the intervals
(1) Less than $25,000,
(2) $25,000-$49,999,
(3) $50,000- $99,999,
(4) $100,000-$249,999, and
5) $250,000 or more.
b. Determine the probability that an individual who has saved for retirement has saved less than $50,000. Use relative frequencies.
c. Determine the probability that a randomly chosen individual has saved less than $50,000 toward retirement.
d. Calculate the probability that at least two of four individuals have saved less than $50,000 toward retirement.
Problem: The ECCO company makes backup alarms for machinery like forklifts and commercial trucks. When a customer returns one of the alarms under warranty, the quality manager logs data on the product. From the data available in the file named Ecco, use relative frequency to find the following probabilities.
a. What is the probability the product was made at the Salt Lake City plant?
b. What is the probability the reason for the return was a wiring problem?
c. What is the joint probability the returned item was from the Salt Lake City plant and had a wiring related problem?
d. What is the probability that a returned item was made on the day shift at the Salt Lake plant and had a cracked lens problem?
e. If an item was returned, what is the most likely profile for the item, including plant location, shift, and cause of problem?