Remember that any question marked with a w requires you to s

Remember that any question marked with a (w) requires you to show/explain how you arrived at your answer. If you used technology, explain exactly what you input, and which functions you used. The histogram below represents randomly selected times between eruptions of Old Faithful geyser in Yellowstone National Park. Use this histogram to answer the following questions: How many observations are represented in the histogram? What is the average length of time between eruptions? What is the median length of time between eruptions? Yellowstone rangers, in 2001, told me \"Old Faithful erupts every 80 to 90 minutes.\" What percentage of the intervals are between 80 and 90 minutes in length (assuming that the data above represents a good random sample of eruption intervals)? What percentage of the intervals are less than 80 minutes in length? What percentage of the intervals are more than 90 minutes in length? Based on your answers, do you think the geyser\'s name (\"Old Faithful\") is appropriate? Why or why not?

Solution

1).

Number of observations =50

2).

class

X

F

X*F

55-60

57.5

3

172.5

60-65

62.5

5

312.5

66-70

67.5

3

202.5

70-75

72.5

2

145

75-80

77.5

7

542.5

80-85

82.5

12

990

85-90

87.5

10

875

90-95

92.5

3

277.5

95-100

97.5

3

292.5

100-105

102.5

2

205

Total

50

4015

Average =4015/50=80.3

3).

Median class = 80-85

Median = 82.5

4).

22 observations between 80 and 90

44%

5).

20 observations are less than 80

40%

6).

8 observations are more than 90

16%

7).

Yes, it is appropriate because its most frequent eruptions( 40%) are between 80 to 90 minutes regularly.

	class	X	F	X*F
	55-60	57.5	3	172.5
	60-65	62.5	5	312.5
	66-70	67.5	3	202.5
	70-75	72.5	2	145
	75-80	77.5	7	542.5
	80-85	82.5	12	990
	85-90	87.5	10	875
	90-95	92.5	3	277.5
	95-100	97.5	3	292.5
	100-105	102.5	2	205
Total			50	4015