Chapter 3 Flashcards
Statistical measures used to yield information about the center or middle part of a
group of numbers are called _______________.
Measures of Central Tendency
. The “average” is the _______________.
Mean
The value occurring most often in a group of numbers is called _______________.
Mode
In a set of 110 numbers arranged in order, the median is located at the
_______________ position.
Mode
If a set of data has an odd number of values arranged in ascending order, the median
is the ________________ value.
Middle
Consider the data: 5, 4, 6, 6, 4, 5, 3, 2, 6, 4, 6, 3, 5
Answer questions 6-8 using this data.
The mode is _______________.
6
Consider the data: 5, 4, 6, 6, 4, 5, 3, 2, 6, 4, 6, 3, 5
Answer questions 6-8 using this data.
The median is _______________.
5
Consider the data: 5, 4, 6, 6, 4, 5, 3, 2, 6, 4, 6, 3, 5
Answer questions 6-8 using this data.
The mean is _______________.
4.54
If a set of values is a population, then the mean is denoted by _______________.
Mu
Measures of variability describe the _______________ of a set of data.
Spread or Dispersion
Use the following population data for Questions 11-14:
27 65 28 61 34 91 61 37 58 31 43 47 44 20 48 50 49 43 19 52 The range of the data is \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
72
Use the following population data for Questions 11-14:
27 65 28 61 34 91 61 37 58 31 43 47 44 20 48 50 49 43 19 52 . The value of Q1 is \_\_\_\_\_\_\_\_\_\_\_\_\_, Q2 is \_\_\_\_\_\_\_\_\_\_\_\_, and Q3 is \_\_\_\_\_\_\_\_\_\_\_\_.
Q1 = 32.5, Q2 = 45.5, Q3 = 55
Use the following population data for Questions 11-14:
27 65 28 61 34 91 61 37 58 31 43 47 44 20 48 50 49 43 19 52 The interquartile range is \_\_\_\_\_\_\_\_\_\_\_\_\_.
IQR = 22.5
Use the following population data for Questions 11-14:
27 65 28 61 34 91 61 37 58 31 43 47 44 20 48 50 49 43 19 52 The value of the 34th percentile is \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
P34 = 37
Subtracting each value of a set of data from the mean produces _______________
from the mean.
Deviations
The sum of the deviations from the mean is always _______________.
Zero
The variance is the _______________ of the standard deviation.
Square
The population variance is computed by using _______________ in the
denominator. Whereas, the sample variance is computed by using
_______________ in the denominator.
N, n – 1
If the sample standard deviation is 9, then the sample variance is
_______________.
81
Consider the data below and answer questions 20-21 using the data:
2, 3, 6, 12
The sample variance for this data is _______________.
20.25
Consider the data below and answer questions 20-21 using the data:
2, 3, 6, 12
The population standard deviation for this data is _______________.
3.897
In estimating what proportion of values fall within so many standard deviations of the mean, an analyst should use if the shape of the distribution of numbers is unknown
Chebyshev’s Theorem
Suppose a distribution of numbers is mound shaped with a mean of 150 and a variance of 225. Approximately _______________ percent of the values fall between 120 and 180. Between _______________ and _______________ fall
99.7% of these values.
95, 105, and 195
The shape of a distribution of numbers is unknown. The distribution has a mean of 275 and a standard deviation of 12. The value of k for 299 is _______________. At least _______________ percent of the values fall between 251 and 299
2, 75
Suppose data are normally distributed with a mean of 36 and a standard deviation of 4.8. The z score for 30 is _______________. The z score for 40 is _______________.
–1.25, 0.83
A normal distribution of values has a mean of 74 and a standard deviation of 21.
The coefficient of variation for this distribution is _______________?
28.38%
If a unimodal distribution has a mean of 50, a median of 48, and a mode of 47, the distribution is skewed _______________.
Right or Positively skewed
Mean > Median > Mode
In a box plot, the inner fences are computed by ___________________ and ____________________. The outer fences are computed
___________________ and ___________________.
Q1 - 1.5 IQR and Q3 + 1.5 IQR
Q1 - 3.0 IQR and Q3 + 3.0 IQR
Data values that lie outside the mainstream of values in a distribution are referred to
as __________________.
Outliers
