10.4 Matched or Paired Samples (Optional)

A study was conducted to investigate how effective a new diet was in lowering cholesterol. Results for the randomly selected subjects are shown in the table. The differences have a normal distribution. Are the subjects’ cholesterol levels lower on average after the diet? Test at the 5 percent level.

A new prep class was designed to improve SAT test scores. Five students were selected at random. Their scores on two practice exams were recorded, one before the class and one after. The data are recorded in the table. Are the scores, on average, higher after the class? Test at a 5 percent level.

Five ball players think they can throw the same distance with their dominant hand (throwing) and off-hand (catching hand). The data were collected and recorded in the table. Conduct a hypothesis test to determine whether the mean 5 difference in distances between the dominant and off-hand is significant. Test at the 5 percent level.

What is the random variable?

What is the p-value?

What conclusion can you draw about the software patch?

What is the p-value?

State the null and alternative hypotheses.

What is the p-value?

What is the conclusion?

Ten individuals went on a low-fat diet for 12 weeks to lower their cholesterol. The data are recorded in the table. Do you think that their cholesterol levels were significantly lowered?

Let the subscript t = treated patient and ut = untreated patient.

If the p-value is 0.0062, what is the conclusion? Use α = 0.05.

1. The method has no effect.
2. There is sufficient evidence to conclude that the method reduces the proportion of patients who develop the disease after four years.
3. There is sufficient evidence to conclude that the method increases the proportion of patients who develop the…

Use the following information to answer the next two exercises. An experiment is conducted to show that blood pressure can be consciously reduced in people trained in a biofeedback exercise program. Six subjects were randomly selected, and blood pressure measurements were recorded before and after the training. The difference between blood pressures was calculated (after – before), producing the f…

A new chocolate bar is taste-tested on consumers. Of interest is whether the proportion of children who like the new chocolate bar is greater than the proportion of adults who like it.

A football league reported that the mean number of touchdowns per game was five. A study is done to determine if the mean number of touchdowns has decreased.

According to a doctor’s magazine, 75 percent of senior citizens think that yearly checkups are very important. A study is done to verify this.

A recent survey showed an increase in use of prescription medication among local senior citizens as compared to the national percent. Suppose that a survey of 100 local senior citizens and 100 national senior citizens is conducted to see if the proportion of prescription medication use is higher locally than nationally.

According to a statistics college professor, 68 percent of his students pass the final exam. A graduate researcher designs a study to determine if this claim is true.

A golf instructor is interested in determining if her new technique for improving players’ golf scores is effective. She takes four new students. She records their 18-hole scores before learning the technique and after having taken her class. She conducts a hypothesis test. The data are shown in the table.

This is

1. a test of two independent means.
2. a test of two proportions.
3. a test of a single mean.
4. …