Height of Men Height inches Freq 613637 1 638662 3 663687 5

Height of Men

Height (inches) Freq

61.3-63.7 1

63.8-66.2 3

66.3-68.7 5

68.8-71.1 16

71.2-73.6 9

73.7-76.1 5

76.2-78.6 1

Class width ?

First class midpoint ?

Upper class boundary for first class interval ?

Solution

Note that class width is the difference between any two consecutive lower bounds.

We can take 61.3 and 63.8 here. Thus,

class width = 63.8 - 61.3 = 2.5 [ANSWER]

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Thus, the midpoint is the average of its lower limit (61.3) and the lower limit of the next class (63.8).

first class midpoint = (63.8+ 61.3)/2 = 62.55 [answer]
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To get the upper class boundary of the first group, we take the average of its upper class limit (63.7) and the lower class limit of the next group (63.8).

Thus,

upper class boundary = (63.7 + 63.8)/2 = 63.75 [ANSWER]