Questions from Statistics

Q: Randomly chosen people were observed for about 10 seconds in several public

Randomly chosen people were observed for about 10 seconds in several public places, such as malls and restaurants, to see whether they smiled during that time. The table shows the results for differen...

Q: The Perry Preschool Project was created in the early 1960s by David

The Perry Preschool Project was created in the early 1960s by David Weikart in Ypsilanti, Michigan. One hundred twenty three African American children were randomly assigned to one of two groups: One...

Q: The Perry Preschool Project data presented in exercise 10.39 (

The Perry Preschool Project data presented in exercise 10.39 (Schweinhart et al. 2005) can be divided to see whether the preschool attendance effect is different for males and females. The table shows...

Q: A 95% confidence interval for the ages of the first six

A 95% confidence interval for the ages of the first six presidents at their inaugurations is (56.2, 59.5). Either interpret the interval or explain why it should not be interpreted.

Q: The Perry Preschool Project data presented in exercise 10.39 can

The Perry Preschool Project data presented in exercise 10.39 can be divided to see whether there are different effects for males and females. The table shows a summary of the data for males (Schweinha...

Q: A 2018 Gallup poll asked respondents if they supported same-sex

A 2018 Gallup poll asked respondents if they supported same-sex marriage. Results are reported by political party in the StatCrunch output that follows. a. Find the percentage in each political party...

Q: Jennifer Brogan, a biology student who was taking a statistics class

Jennifer Brogan, a biology student who was taking a statistics class, exposed similar tomato plants to different colors of light. The average growth rates (in millimeters per week) are given in the ta...

Q: A random sample of students was studied. Whether the student chose

A random sample of students was studied. Whether the student chose to sit in the front, middle, or back row in a college class was observed, along with the person’s GPA. Test the hyp...

Q: Sixty-six reading students were randomly assigned to be taught using

Sixty-six reading students were randomly assigned to be taught using one of three teaching methods. One method is called Basal and uses textbooks that are organized to develop reading skills. Another...

Q: In a 2017 study published in the journal Food Quality and Preference

In a 2017 study published in the journal Food Quality and Preference, researchers investigated the effect of drinking tea on divergent creativity (Huang et al. 2017). Subjects were recruited from a ca...