Midterm 1 Practice Test

1. A polling company reported that 71% of 2,513 surveyed adults said that they play football. What is the exact value that is 71% of 2,513? (Exact calculations may result in decimals.  Please round to the nearest hundredth.)

2.   A study was conducted of all 1134 car owners in a certain country. The average age of the owners is calculated. Determine whether the average age of the owners is a statistic or a parameter.

1.   The value is a statistic because it is a numerical measurement describing some characteristic of a sample. 
2.   The value is a parameter because it is a numerical measurement describing some characteristic of a sample. 
3.   The value is a statistic because it is a numerical measurement describing some characteristic of a population.
4.   The value is a parameter because it is a numerical measurement describing some characteristic of a population. 

3.  The height of 2-year-old maple tree is 28 ft. Does the data come from a discrete or continuous data set?

1.   A discrete data set because the possible values can be counted. 
2.   A continuous data set because there are infinitely many possible values and those values can be measured.
3. A continuous data set because there are infinitely many possible values and those values can be counted.
4. The data set is neither continuous nor discrete. 

4.  Ages of children. Which level of measurement is most appropriate for this data?

1. interval  
2. nominal 
3. ordinal 
4. ratio 

5.   In a poll conducted by a certain research center, 824 adults were called after their telephone numbers were randomly generated by a computer, and 10% were able to correctly identify the president. Identify the type of sampling used.

1. systematic   
2. stratified 
3. random
4. convenience 
5. cluster 

6.  An ad for seat belts claimed that proper usage of seat belts “reduces the chance of fatality in a car crash by 400 percent.” What is wrong with this statement? Choose the correct answer below.

1. If fatalities fell by 100%, it would be cut in half. Thus, a decrease of 200% means that it would be totally eliminated, and a decrease of more than 200% is impossible. 
2. If seat belts eliminated all fatalities, it would result in a 100% reduction, so it is not possible to reduce fatalities by more than 100 %.
3. The statement does not mention the initial amount of fatalities.
4. The actual amount of the decrease in fatalities is less than 100%. 

7.  Subscribers of the women’s magazine Cosmopolitan are asked to participate in a survey about preferred cereals for breakfast. Are the results likely to be representative of all women? Of all subscribers of Cosmopolitan? Why or why not?

8.   The data represents the body mass index (BMI) values for 20 females. Construct a frequency distribution beginning with a lower class limit of 15.0 and use a class width of 6.0. What frequency is listed for the seventh class?
20.1, 23.6, 30.8, 36, 41.1, 48.2, 52.7, 37.8, 32.8, 41, 51.5, 15.5, 42.5, 34.8, 18.9, 28.9, 47.7, 41.4, 30.4, 24.7

9. The frequency table below shows the number of days off in a given year for police detectives. Construct a histogram. What is the lower class boundary of the sixth class?

10.  A parcel delivery service lowered its prices and finds that it has delivered twice as many parcels this year as it did last year. To illustrate this fact, the manager draws a cube for last year and a cube for this year with a side length twice the length of last year’s cube.  Draw the manager’s graph. Why is this graph misleading? What visual impression is created by the graph?

11.   The weights (in pounds) of six dogs are listed below. Find the mean weight. Round your answer to one more decimal place than is present in the original data values.

78, 129, 136, 47, 138, 90

12.    The amount of time (in hours) that Sam studied for an exam on each of the last five days is given below. Find the median study time. Round your answer to one more decimal place than is present in the original data values.

2.1, 9.3, 1.9, 7.3, 9.4

13.    Find the mode(s) for the given sample data. (If there are more than one, enter the largest value for credit. If there is no mode, enter 0 for credit.)

1, 1, 1, 1, 2, 2, 2, 9

14.  The students in Hugh Logan’s math class took the Scholastic Aptitude Test. Their math scores are shown below. Find the standard deviation of the score. Round your answer to one more decimal place than is present in the original data values.

267, 273, 452, 371, 539, 205, 729,667, 483, 547

15.  The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency distribution below summarizes the results. Find the standard deviation of the frequency distribution. Round your answer to one more decimal place than is present in the original data values.

16.  A department store, on average, has daily sales of $81.73. The standard deviation of sales is $9.22. On Tuesday, the store sold $111.06 worth of goods. Find Tuesday’s z score.

17.  A test score of 75 on a test having a mean of 68 and a standard deviation of 10. Determine if the value is unusual. Explain. Enter the number that is being interpreted to arrive at your conclusion rounded to the nearest hundredth.

18   Use the given sample data to find Q3. 

42, 53, 69, 51, 47, 65, 45, 56

19.    Find the percentile for the data value.

Data set: 85, 39, 73, 29, 50, 60, 98, 61, 63, 61, 19, 22, 62, 99, 24, 40;

data value: 98

20.    Which is better, a score of 72 on a test with a mean of 71 and a standard deviation of 9, or a score of 265 on a test with a mean of 249 and a standard deviation of 25? Enter the better test score.

21. The weights (in pounds) of 25 newborn babies are listed below. Construct a boxplot for the data set. Enter the maximum value.

4.9, 4.6, 5, 10.4, 11.4, 6, 9.2, 8.4, 6.9, 7.2, 7, 12, 6.8, 5.1, 10.7, 4.5, 7.4, 7.2, 7.3, 8.2, 10, 4.4, 8, 5.2, 6.3