Question

12. A certain group of test subjects had pulse rates with a mean of

84.484.4

beats per minute and a standard deviation of

11.211.2

beats per minute. Use the range rule of thumb to identify the limits separating values that are significantly low or significantly high. Is a pulse rate of

56.856.8

beats per minute significantly low or significantly​ high?

Significantly low values are

nothing

beats per minute or lower.

​(Type an integer or a decimal. Do not​ round.)

14. If your score on your next statistics test is converted to a z​ score, which of these z scores would you​ prefer:

minus−​2.00,

minus−​1.00,

​0, 1.00,​ 2.00? Why?

A.

The z score of

minus−2.00

is most preferable because it is 2.00 standard deviations below the mean and would correspond to the highest of the five different possible test scores.

B.

The z score of 0 is most preferable because it corresponds to a test score equal to the mean.

C.

The z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores.

D.

The z score of 1.00 is most preferable because it is 1.00 standard deviation above the mean and would correspond to an above average test score.

E.

The z score of

minus−1.00

is most preferable because it is 1.00 standard deviation below the mean and would correspond to an above average test score.

15.Researchers measured the data speeds for a particular smartphone carrier at 50 airports. The highest speed measured was

78.678.6

Mbps. The complete list of 50 data speeds has a mean of

x overbarxequals=15.7615.76

Mbps and a standard deviation of

sequals=19.1619.16

Mbps.

a. What is the difference between​ carrier's highest data speed and the mean of all 50 data​ speeds?

b. How many standard deviations is that​ [the difference found in part​ (a)]?

c. Convert the​ carrier's highest data speed to a z score.

d. If we consider data speeds that convert to z scores between

minus−2

and 2 to be neither significantly low nor significantly​ high, is the​ carrier's highest data speed​ significant?

a. The difference is

nothing

Mbps.

​(Type an integer or a decimal. Do not​ round.)

16. Use z scores to compare the given values.

The tallest living man at one time had a height of

264

cm. The shortest living man at that time had a height of

118.8

cm. Heights of men at that time had a mean of

174.85

cm and a standard deviation of

8.49

cm. Which of these two men had the height that was more​ extreme?

Since the z score for the tallest man is

Z equals=nothing

and the z score for the shortest man is

z equals=nothing ​,

the

▼

tallest

shortest

man had the height that was more extreme.

​(Round to two decimal​ places.)

17. se z scores to compare the given values.

Based on sample​ data, newborn males have weights with a mean of

3211.3

g and a standard deviation of

614.3

g. Newborn females have weights with a mean of

3013.9

g and a standard deviation of

811.7

g. Who has the weight that is more extreme relative to the group from which they​ came: a male who weighs

1500

g or a female who weighs

1500

​g?

Since the z score for the male is

zequals=nothing

and the z score for the female is

zequals=nothing ​,

the

▼

male

female

has the weight that is more extreme.

​(Round to two decimal​ places.)

18. Fill in the blank.

A data value is considered​ _______ if its​ z-score is less than

minus−2

or greater than 2.

A data value is considered

▼

significantly low or significantly high

normal

weak

standardized

if its​ z-score is less than

minus−2

or greater than 2.

Answer 1

12)

sig. low value =μ-2*σ =		62.00
sig. high value =μ-2*σ =		106.80

56.8 is significantly low

14)

C) The z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores.

15)

a)difference between​ carrier's highest data speed and the mean of all 50 data​ speeds =78.6-15.76=62.84

b)standard deviations =62.84/19.16=3.28

c) z score =3.28

d) significantly high

16) Since the z score for the tallest man is (264-174.85)/8.49=10.50

and the z score for the shortest man is (118.8-174.85)/8.49=-6.60

tallest man had the height that was more extreme.

17)\

Since the z score for the male is (1500-3211.3)/614.3=-2.79

and the z score for the female is (1500-3013.9)/811.7=-1.87

male has the weight that is more extreme.

18)

A data value is considered significantly low or significantly high

if its​ z-score is less than

minus−2

or greater than 2.