Unit 2 Review
A student collected data on the size of coffee chosen by customers at a convenience store, and whether the customers took their coffee with sugar, cream, or both. Size of Coffee SmallMediumLargeTotalCoffee AdditiveCream8152144Sugar481123Both15234280 Total274674147 What percentage of customers chose a medium-sized coffee? 31.3% 32.6% 50.3% 62.1%
a
A waitress wondered if there was an association between the type of food and the type of drink customers ordered. The results are displayed below. Based on the graph, is there an association between food ordered and drink ordered? There is an association because the distribution of drinks ordered differs among the food groups. There is an association because the distribution of drinks ordered is the same among the food groups. There is no association because the distribution of drinks ordered differs among the food groups. There is no association because the distribution of drinks ordered is the same among the food groups.
a
As an introduction to probability, a student is asked to roll a fair, six-sided number cube seven times. The results of those seven rolls are shown below. 1, 4, 4, 4, 4, 6, 5 What is the IQR of the data? 1 1.53 2 5
a
Data were collected from a typing class with 10 students. The class had an average of 56 words per minute (WPM) with a standard deviation of 7 WPM. The teacher realized that the data from one student who typed 70 WPM was not entered. If this student's results were included in the data set, what effect would it have on the standard deviation? The standard deviation would be noticeably larger. The standard deviation would be noticeably smaller. The standard deviation would be about the same, perhaps a little larger. The standard deviation would be about the same, perhaps a little smaller.
a
The eye color for students in a statistics class was recorded. The relative frequencies for each color are listed in the table below. Which of the following is the missing value? 0.27 0.30 0.37 0.50
a
A statistics student gave a survey to students which asked how many first cousins they have. The data from the first nine responses are shown below. 6, 2, 7, 8, 8, 8, 5, 10, 10 What is the standard deviation of the data? 2.38 first cousins 2.52 first cousins 5.65 first cousins 6.36 first cousins
b
Which of the following displays is a relative frequency bar graph?
b
A school administrator asks each student if they participate in a sport and if they participate in a club. The results are shown below. Participates in a Sport YesNoTotalParticipates in a ClubYes6204501070No325535860 Total9459851930 What percentage of students do not participate in a sport? 27.7% 44.6% 51.0% 62.2%
c
A simple random sample of 10 people were asked how many first cousins they have. The results are listed below. 10, 19, 20, 13, 13, 2, 10, 8, 25, 10 What is the mean number of first cousins for this sample? 10 11.5 13 13.5
c
Brand A and brand B of frozen green beans both list a weight of 32 ounces on their bags. Because of variability in the manufacturing process, the bags often contain slightly more, or less, than 32 ounces of green beans. An inspector takes a random sample of 25 bags of green beans of each type and records their weights. The weights and their relative frequencies are summarized in the histograms. Which of the following is a true statement when comparing the bags of green beans? The median weight for both types is between 32.1 and 32.2 ounces. The median weight for both types is between 32.0 and 32.1 ounces. The median weight for brand B is less than the median weight of brand A. The median weight for brand B is greater than the median weight of brand A.
c
In a statistics class, students were asked how many siblings they have. The mean number of siblings for the class is 3.08 with a standard deviation of 1.61 siblings. The z-score for a student with four siblings is 0.57. Which of the following statements is the best interpretation of the z-score? The number of siblings for this student is in the 57th percentile. This student has 0.57 fewer siblings than the mean number of siblings The number of siblings for this student is 0.57 standard deviations above the mean number of siblings. The number of siblings for this student is 0.57 standard deviations below the mean number of siblings.
c
A brand of frozen green beans lists a weight of 32 ounces on its bag. Because of variability in the manufacturing process, the bags often contain slightly more, or less, than 32 ounces of green beans. An inspector takes a random sample of 25 bags of green beans and records their weights. The weights and their relative frequencies are summarized in the histogram below. Which interval contains the median bag weight? 31.9-32.0 ounces 32.0-32.1 ounces 32.1-32.2 ounces 32.2-32.3 ounces
d
High school students were asked if they preferred fiction or nonfiction books. The results are displayed below. Which of the following statements is true, according to the graph? The lowest percentage of those preferring nonfiction is among 9th-grade students. The highest percentage of those preferring nonfiction is among 12th-grade students. The percentage of those preferring fiction and nonfiction is equal among 11th-grade students. The percentage of preference for each type of book is relatively equal among the different grades of students.
d
The scores for 21 students on an exam are summarized in the stemplot below. The teacher realizes that a mistake was made and the student whose score was recorded as 49% should have been 69%. If the mistake is corrected, what effect will this have on the mean and median scores? The mean and median will both increase. Neither the mean nor the median will change. The mean will increase but the median will decrease. The mean will increase but the median will be unchanged.
d
The side-by-side stemplot below displays the arm spans, in centimeters, for two classes. Which statement correctly compares the arm spans for Class A to those of Class B? The mean arm span for Class A is much lower than Class B's. The mean arm span for Class B is much lower than Class A's. The mean arm span for Class A is much higher than Class B's. The mean arm span for Class B is about the same as Class A's.
d
