Chi Ap Stat

The appropriate null hypothesis for performing a chi-square test is that

• equal proportions of female and male teenagers are almost certain they will be married in 10 years.

• there is no difference between the distributions of female and male teenagers' opinions about marriage in this sample.

• there is no difference between the distributions of female and male teenagers' opinions about marriage in the population.

• there is no association between gender and opinion about marriage in the sample.

• there is no association between gender and opinion about marriage in the population.

A bag contains chips of which 27.5 percent are blue. A random sample of 5 chips will be selected one at a time and with replacement. What are the mean and standard deviation of the sampling distribution of the sample proportion of blue chips for samples of size 5 ?

• The mean is 0.275, and the standard deviation is 0.250

• The mean is 0.275, and the standard deviation is 0.156

• The mean is 0.275, and the standard deviation is 0.200.

• The mean is 0.275, and the standard deviation is 0.350

• The mean is 0.275, and the standard deviation is 0.1.00

The table shows the results of a survey in which 146 families were asked if they own a computer and if they will be taking a summer vacation during the current year. Find the probability that a randomly selected family is taking a summer vacation this year, given that they own a computer.

• 0.6

• 0.757

• 0.9

• 0.308

• 0.596

The following data were collected from a random sample of people, who identified their favorite type of juice. The results are shown in the following two-way table.

What proportion of the children identified orange as their favorite type of juice?

• 
• 
• 
• 
• 

Which of the following shapes is NOT represented by one of the four distributions?

• Uniform

• Bimodal

• Skewed to the left

• Skewed to the right

• Symmetric and unimodal

A school is having a contest in which students guess the number of candies in a jar. The student whose guess is closest to the correct number of candies in the jar wins a prize. The number of candies guessed by male and female students is shown in the back-to-back stemplot.

Which of the following statements is true about the distributions of guesses?

• The distribution of guesses for male students is skewed to the left, and the distribution of guesses for female students is skewed to the right.

• The distribution of guesses for male students is skewed to the right, and the distribution of guesses for female students is skewed to the left.

• The distributions of guesses for male and female students are both skewed to the right.

• The distributions of guesses for male and female students are both skewed to the left.

• The distributions of guesses for male and female students are both symmetric.

A car rental agency has two locations in a city. The boxplots below summarize the miles driven for one day of single-day car rentals at each location.

Based on the boxplots, which statement provides the best comparison of the two locations?

• The number of single-day rentals is greater for location A than for location B.

• The number of single-day rentals is less for location A than for location B.

• Compared with location A, the miles driven for location B display more variability, and the median is greater.

• Compared with location A, the miles driven for location B display less variability, and the median is greater.

• Compared with location A, the miles driven for location B display less variability, and the median is about the same.

A random sample of 374 United States pennies was collected, and the age of each penny was determined. According to the boxplot, what is the approximate interquartile range (IQR) of the ages?

• 10

• 12

• 16

• 20

• 8

A local real estate magazine used the median instead of the mean when it reported the SAT score of the average student who attends Groveland High School. A graphical display of SAT scores of students who attend Groveland High School indicated that the data were strongly skewed to the right. Which of the following explains why, in this situation, the median is a more accurate indicator of the SAT score of the average student than the mean is?

• The mean is affected by the skewness, whereas the median is not.

• The median is always the preferred statistic.

• The mean will be less than the median when the data are strongly skewed to the right.

• The mean should be used only when data are strongly skewed to the left.

• The median is equal to one-half the sum of the maximum and minimum SAT scores at Groveland High.

The dotplot below displays the total number of miles that the 28 residents of one street in a certain community traveled to work in one five-day workweek.<\/p>

Which of the following is closest to the percentile rank of a resident from this street who traveled 85 miles to work that week?<\/p>

• 60<\/p>

• 70<\/p>

• 75<\/p>

• 80<\/p>

• 65<\/p>