Questions from Applied Statistics

Q: The Environmental Protection Agency (EPA) requires that cities monitor over

The Environmental Protection Agency (EPA) requires that cities monitor over 80 contaminants in their drinking water. Samples from the Lake Huron Water Treatment Plant gave the results shown here. Only...

Q: A study showed that fourteen of 180 publicly traded business services companies

A study showed that fourteen of 180 publicly traded business services companies failed a test for compliance with Sarbanes-Oxley requirements for financial records and fraud protection. Assuming that...

Q: How “decaffeinated” is decaffeinated coffee? If a researcher wants

How “decaffeinated” is decaffeinated coffee? If a researcher wants to estimate the mean caffeine content of a cup of Starbucks’ decaffeinated espresso with 98 percent confidence and an error of ±0.1 m...

Q: Junior Achievement and Deloitte commissioned a “teen ethics poll” of

Junior Achievement and Deloitte commissioned a “teen ethics poll” of 787 students aged 13–18, finding that 29 percent felt inadequately prepared to make ethical judgments. (a) Assuming that this was a...

Q: A random sample of 30 cans of Del Vino crushed tomatoes revealed

A random sample of 30 cans of Del Vino crushed tomatoes revealed a mean weight of 798.3 grams (excluding the juice). The can-filling process for Del Vino crushed tomatoes has a known standard deviatio...

Q: A poll of 125 college students who watch The Big Bang Theory

A poll of 125 college students who watch The Big Bang Theory showed that 83 of them usually watch on a mobile device (e.g., laptop). (a) Assuming that this was a random sample, construct a 90 percent...

Q: A survey of 4,581 U.S. households that

A survey of 4,581 U.S. households that owned a mobile phone found that 58 percent are satisfied with the coverage of their cellular phone provider. Assuming that this was a random sample, construct a...

Q: A “teen ethics poll” was commissioned by Junior Achievement and

A “teen ethics poll” was commissioned by Junior Achievement and Deloitte. The survey by Harris Interactive surveyed 787 students aged 13–18. (a) Assuming that this was a random sample of all students...

Q: July sales for Melodic Kortholt, Ltd., average μ1 = $

July sales for Melodic Kortholt, Ltd., average μ1 = $9,500 with σ1 2 = $1,250. August sales average μ2 = $7,400 with σ2 2 = $1,425. September sales average μ3 = $8,600 with σ3 2 = $1,610. (a) Find the...

Q: Biting an unpopped kernel of popcorn hurts! As an experiment,

Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, the unpopped kernels...