Statistics Homework
halaja
optional_homework_first_test-2.docxName________________
Optional HW (Chapter 1-3 Test)
Due 2/20/15
1. The amount of television viewed by today’s youth is of primary concern to Parents Against Watching Television (PAWT). 300 parents of elementary school-aged children were asked to estimate the number of hours per week that their child watched television. The mean and the standard deviation for their responses were 16 and 4, respectively. PAWT constructed a stem-and-leaf display for the data that showed that the distribution of times was a bell-shaped distribution.
a. Give an interval around the mean where you believe most (approximately 95%) of the television viewing times fell in the distribution.
b. Why do we need to know that the stem-and leaf plot showed the distribution was bell-shaped?
2. A student scores 56 on a geography test and 285 on a mathematics test. The geography test has a mean of 80 and a standard deviation of 20. The mathematics test has a mean of 300 and a standard deviation of 10. If the data for both tests are normally distributed, on which test did the student score better relative to the other students in each class? (Show all necessary work needed to answer the question.)
3. When results from a scholastic assessment test are sent to test-takers, the percentiles associated with their scores are also given. Suppose a test-taker scored at the 99th percentile for their verbal grade and at the 36th percentile for their quantitative grade. Interpret these results.
