Questions from Business Statistics

Q: Describe how the shape, center, and spread of t-

Describe how the shape, center, and spread of t-models change as the number of degrees of freedom increases.

Q: A very large study showed that aspirin reduced the rate of first

A very large study showed that aspirin reduced the rate of first heart attacks by 44%. A pharmaceutical company thinks they have a drug that will be more effective than aspirin, and plans to do a rand...

Q: Here are boxplots of weekly gas prices for regular gas in the

Here are boxplots of weekly gas prices for regular gas in the United States as reported by the U.S. Energy Information Administration for 2000 through 2018: 1. Compare the distribution of prices over...

Q: In 1960, census results indicated that the age at which American

In 1960, census results indicated that the age at which American men first married had a mean of 23.3 years. It is widely suspected that young people today are waiting longer to get married. We want t...

Q: A researcher tests whether the mean cholesterol level among those who eat

A researcher tests whether the mean cholesterol level among those who eat frozen pizza exceeds the value considered to indicate a health risk. She gets a P-value of 0.07. Explain in this context what...

Q: The United States Golf Association (USGA) sets performance standards for

The United States Golf Association (USGA) sets performance standards for golf balls. For example, the initial velocity of the ball may not exceed 250 feet per second when measured by an apparatus appr...

Q: Occasionally, a report comes out that a drug that cures some

Occasionally, a report comes out that a drug that cures some disease turns out to have a nasty side effect. For example, some antidepressant drugs may cause suicidal thoughts in younger patients. A re...

Q: Developing a new drug can be an expensive process, resulting in

Developing a new drug can be an expensive process, resulting in high costs to patients. A pharmaceutical company has developed a new drug to reduce cholesterol, and it will conduct a clinical trial to...

Q: A friend of yours claims to be psychic. You are skeptical

A friend of yours claims to be psychic. You are skeptical. To test this you take a stack of 100 playing cards and have your friend try to identify the suit (hearts, diamonds, clubs, or spades), withou...

Q: For each of the following situations, define the parameter (proportion

For each of the following situations, define the parameter (proportion or mean) and write the null and alternative hypotheses in terms of parameter values. Example: We want to know if the proportion o...