Stats Quiz 2

The mean of {-3, -1, -1, -1, -3, 3} is

-1

The median of {-5, -3, -3, -3, -5, 1} is

-4

Find the weighted mean for three exams if the first one was worth 75 points and the student received a score of 70%, the second was worth 50 points and the student received a score of 80% and the third was worth 30 points and the student received a score of 95%?

78.1

Given the following data set, find the value that corresponds to the 75th percentile. 10, 44, 15, 23, 14, 18, 72, 56

50

find Q^1,Q^2,Q^3 for the following data set. 7, 21, 32, 38. A). Q^1=14, Q^2=265, Q^3=35 B). Q^1=10, Q^2=25, Q^3=36 C). Q^1=5, Q^2=20, Q^3=39 D). Q^1=14, Q^2=25, Q^3=25

A

Which of the following is true? A) D^5=P^5=Q^5 B) D^50=P^5=Q^25 C) D^5=P^50=Q^2 D) D^50=P^5=Q^2

C

For the table below, calculate the cumulative percent of the students that fell within the B class. A) 14% B) 25% C) 11% D) 39%

D

A normal distribution in which approximately 68% of the data values fall within one standard deviation of the mean behaves according to A) the empirical rule. C) a boxplot. B) a symmetrical distribution. D) differential statistics.

a

Given that the variance for a data set is 1.20, what would be the standard deviation? A) 1.10 B) 1.44 C) 1.20 D) 0.60

a

Given the following boxplot where m is the median value, what statement could be made about the distribution of the data? A) The distribution is approximately symmetric. B) The distribution is positively skewed. C) The distribution is negatively skewed. D) No statement can be made about the data because no data values are shown on the plot.

a

If a set of 9 numbers has standard deviation 10, then it's variance is A) 100.00 B) 3.33 C) 33.33 D) 30.00

a

If the mean of a set of data is 20.00, and 26.00 has a z-score of 0.75, then the standard deviation must be: A) 8.00 B) 64.00 C) 4.00 D) 32.00

a

What is the range of the numbers -5, 1, -7, 2, 10 A) -5 B) 1 C) 3 D) 17

d

A five-number summary of a data set consists of the minimum, Q^1, the mean, Q^3, and the maximum. true or false

false

For a set of data with mean 30 and variance 16, approximaely 68% of the values will fall between 22 to 38. true or false

false

For the sample 1, 8, 7, 2, 9, 15, and 18, the mean is 7.6. true or false

false

The coefficient of variation is the mean divided by the standard deviation expressed as a percentage. true or false

false

The interquartile range or IQR is found by subtracting the mean from the maximum value of a data set. true or false

false

The variance is the square root of the standard deviation of a set of data. true or false

false

Find the mean, mode, median, and midrange value for the following data set. 12, 15, 18, 18, 15, 22, 15, 30, 12

mean = 17.4, mode = 15, median = 15, and midrange value = 21

The grades for a trigonometry exam follow. Find the range. 85, 76, 93, 82, 84, 90, 75 A) 76 B) 9 C) 11 D) 18

d

The range of the set of numbers {6, 13, 3, 10, 5} is A) 3 B) 13 C) 8 D) 10

d

The mean of {6, 13, 11, 9, 11} is

10

The median of {-1, 6, 3, 2, -1} is

2

If a sample of data has mean 12 and variance 25, then it's coefficient of variation is

2.4

The range of the dataset {-5, -9, 0, 11, -2} is

20

The maximum of the set of numbers {6, 15, -5, 11, 5} is A) -5 B) 15 C) 9 D) 12

b

A stem and leaf plot is a data plot that uses part of a data value as the stem and part of the data value as the leaf to form groups or classes. true or false

true

A weighted mean is used when the values of the data set are not all equally represented. true or false

true

Chebyshev's theorem can be used to find the minimum percentage of data values that will fall between any two given values. true or false

true

Methods commonly called traditional statistics include using measures of position, Chebyshev's theorem, and the coefficient of variation. true or false

true

The median can be a more appropriate measure of central tendency if the distribution of the data is extremely skewed. true or false

true

The percentile corresponding to a given value X is computed by adding the 0.5 to number of values below X and dividing this value by the total number of values within the data set. true or false

true

The range of a data set is the distance between the highest value and the lowest value. true or false

true

The unbiased estimator is included in the formula for calculating the variance of a sample because without it, the computed variance usually underestimates the population variance. true or false

true

A student received the following grades: An A in Statistics (4 credits), a B in Physics II (5 credits), a B in Sociology (3 credits), a B in a Literature seminar (2 credits), and a D in Tennis (1 credit). Assuming A = 4 grade points, B = 3 grade points, C = 2 grade points, D = 1 grade point, and F = 0 grade points, the student's grade point average is: A) 3.00 B) 3.47 C) 3.24 D) 3.12

b

All the values in a dataset are between 6 and 15, except for one value of 85. That value 85 is likely to be A) the range B) an outlier C) the mean D) the boxplot

b

If the mean of a set of data is 24.00, and 18.40 has a z-score of -1.40, then the standard deviation must be: A) 4.00 B) 16.00 C) 2.00 D) 8.00

a

The minimum of the set of numbers {-2, 16, -5, 11, 5} is A) -2 B) 16 C) 9.5 D) 18

a

What is the correct standard score for a batter who normally averages 0.325, with a standard deviation of 0.065 if he scores 0.410 for one game? A) 1.308 B) 0.410 C) 0.325 D) 1.275

a

What is the midrange of the following numbers? 7, 13, 12, 14, 6, 14, 20, 20, 20 A) 13 B) 14 C) 7 D) 20

a

Find the mode for the number of police officers in selected city districts. 24, 26, 24, 30, 23, 28, 19, 31, 24, 26, 19 A) 23 B) 24 C) 26 D) 28

b

Find the z score for each student and indicate which one is higher. Art Major Theater major A) The art major has a higher score than the theater major. B) The theater major has a higher score than the art major. C) Both students have the same score. D) Neither student received a positive score; therefore, the higher score cannot be determined.

b

Given that the mean of a set of data is 25 and the standard deviation is 3, what would be the coefficient of variation? A) 0.12 B) 12% C) 8.33 D) 833%

b

In a unimodal, symmetrical distribution as shown in the figure below. A) The mean is the same as the median, but the mode can be different. B) The mean, the median, and the mode are the same. C) The median and the mode are the same, but the mean can be different. D) The mean, the median, and the mode are different.

b

What is the mean of the following numbers? -13, -10, -6, -5, -1 A) -10 B) -7 C) -6 D) -3

b

What is the median of the following numbers? -12, -9, -5, -4, 0 A) -6 B) -5 C) -4 D)-2

b

What is the median of the following numbers? -13, 1, -1, -5, -1, -6, -5, -1 A) -7 B) -3 C) -5 D) -1

b

Which of the following is the correct mean for the given data? 7, 8, 13, 9, 10, 11 A) 10 B) 9.7 C) 9.67 D) 9

b

Determine the range for this data: 7, 15, 11, 9, 23 A) 7 B) 11 C) 16 D) 23

c

Find the median for the following data. 6, 7, 4, 5, 3, 7, 4 A) 3 B) 4 C) 5 D) 7

c

In the figure below, what class boundary has 30% of the data? A) 0.5-20.5 B) 20.5-40.5 C) 40.5-60.5 D) 60.5-80.5

c

What is the mean of the following numbers? 1, 3, 6, 8, 12 A) 3 B) 5 C) 6 D) 7

c

What is the median of the following numbers? 3, 5, 8, 10, 14 A) 5 B) 7 C) 8 D) 9

c

Which of the following is the mode for the given data? 5, 4, 3, 4, 5, 6, 5, 5, 3, 4 A) 3 B) 4 C) 5 D) 6

c

According to Chebyshev's theorem, the proportion of values from a data set that is further than 2 standard deviations from the mean is: A) 0.50 B) 0.13 C) 1.00 D) 0.25

d

Determine the range for this data: 4, 7, 3, 16, 5, 22, and 8. A) 4 B) 3 C) 14 D) 19

d

If a set of data has 49 points and variance 36, then the standard deviation is A) 5.14 B) 0.12 C) 0.86 D) 6.00

d

If a student scored 70 points on a test where the mean score was 78 and the standard deviation was 6. The student's z-score was A) 13.00 B) 0.22 C) -0.22 D) -1.33

d

If a student scored 86 points on a test where the mean score was 80 and the standard deviation was 3. The student's z-score was A) 26.67 B) 28.67 C)0.67 D) 2.00

d

If the boxplot for one set of data is much wider than the boxplot for a second set of data, then A) the mean of the first set of data must be larger than the mean of the second set of data B) the median of the first set of data must be larger than the median of the second set of data C) the second set of data must contain several outliers D) none of the above need to be true

d

If the five number summary for a set of data is -2, 1, 4, 5, and 14, then the mean of this set of data is A) 6 B) 4 C) 3 D) there is insufficient information to calculate the mean

d

If the value 7 has z-score of -1 in a dataset, then the mean of that dataset is A) 7 B) 6 C) 8 D) It cannot be determined from the data given

d

What is the mode of the following numbers? -12, 2, 0, -4, 0, -2, -5 A) -6 B) -2 C) -4 D) 0

d