AnswersOK-Algebra II - Sem B -CA- 35031BUnit Test

Standard Deviation Answers

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1
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What is the variance?

Answers:
Selection 1:864
Selection 2:29.4
2
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Why does the formula use “n – 1” in the denominator?

A
The data is a sample and is expected to be more dispersed from the mean.
B
The data is a sample and is expected to be less dispersed from the mean.
C
The data is a population and is expected to be more dispersed from the mean.
D
The data is a population and is expected to be less dispersed from the mean.
4

Question text not available

Answers:
Blank 1:standard deviations
Blank 2:mean
5

The z-score is the number of [___] a data value is away from the [___].

Answer:

mean

6

A contractor records the areas, in square feet, of several houses in a neighborhood to determine data about the neighborhood. Which formula should be used to calculate the standard deviation?

A
Option
B
Option
C
Option
D
Option
7

What is the variance?

Answer:

84000

8

Which of the following represents the numerator in the calculation of variance and standard deviation?

A
(225)2 + (–425)2 + (–275)2 + (325)2 + (75)2 + (–75)2 = 423,750
B
(650)2 + (–150)2 + (–600)2 + (250)2 + (150)2 + (–300)2 = 980,000
C
(250)2 + (–400)2 + (–250)2 + (350)2 + (100)2 + (–50)2 = 420,000
9

Question text not available

Answers:
Blank 1:84000
Blank 2:290
10

z1 = [___]

Answer:

-1.95

11

Given that z = –2 and z = –1, which of the following do you know?

Question illustration
A
The variance is 10.
B
The standard deviation is 30.
C
The mean is 80.
D
The median is 40.
E
The data point x = 20 is 2 standard deviations from the mean.
F
The data point x = 50 is 1 standard deviation from the mean.
G
The data point x = 45 has a z-value of 1.5.
12

The data value x exists in two data sets: A and B. The mean is equal for both data sets. If the standard deviation for set A is greater than the standard deviation for set B, which is true for zx for set A?

A
It is equal to zx for set B.
B
It is less than zx for set B.
C
It is greater than zx for set B.
13

Which formula should be used to calculate the variance?

Answer:

sigma^2 = sum(x - mu)^2 / n

14

What is the variance?

Answer:

32

15

The data set on the right represents .

A
a sample of the population
B
the population
16

What is the standard deviation, rounded to the nearest whole number?

Answer:

290

17

The z-score is the number of [___] a data value is away from the [___].

Answer:

standard deviations

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