1.Often, frequency distributions are reported using unequal class widths because the frequencies of some groups would otherwise be small or very large. Consider the followingdata, which represent the daytime household temperature the thermostat is set to when someone is home for a random sample of 743 households. Determine the classmidpoint, ifnecessary, for each class and approximate the mean and standard deviation temperature.

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Click the icon to view the frequency distribution for the daytime household temperature.

Class

Class Midpoint

61-

64

nothing

65-

67

nothing

68-

69

nothing

70

nothing

71-

72

nothing

73-

76

nothing

77-

80

nothing

(Round to one decimal place asneeded.)

2.Recently, a random sample of 25-34 year olds wasasked, "How much do you currently have insavings, not including retirementsavings?" The data in the table represent the responses to the survey. Approximate the mean and standard deviation amount of savings.

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Click the icon to view the frequency distribution for the amount of savings.

The sample mean amount of savings is $

nothing

.

(Round to the nearest dollar asneeded.)

3.The frequency distribution was obtained using a class width of 0.5 for data on cigarette tax rates. Use the frequency distribution to approximate the population mean and population standard deviation. Compare these results to the actual mean =$1.563 and standard deviation =$0.995.

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Click the icon to view the frequency distribution for the tax rates.

The population mean is $

nothing

.

(Round to three decimal places asneeded.)

4.Clarissa has just completed her second semester in college. She earned a grade of B in her 3-hour calculus course, a grade of A in her 4-hour psychology course, a grade of B in her 2-hour chemistry course, and a grade of F in her 3-hour speechwriting course. Assuming that A equals 4points, B equals 3points, C equals 2points, D equals 1point, and F is worth nopoints, determine Clarissa's grade-point average for the semester.

Clarissa's grade point average is

nothing

.

(Round to two decimal places asneeded.)

5.InMarissa's calculuscourse, attendance counts for 5% of thegrade, quizzes count for 15% of thegrade, exams count for 60% of thegrade, and the final exam counts for 20% of the grade. Marissa had a 100% average forattendance, 89% forquizzes, 86% forexams, and 85% on the final. DetermineMarissa's course average.

Marissa's course average is

nothing

%. (Type an integer or a decimal. Do notround.)

6.Male and female populations of tortoises under 80 years old are represented by age in the table below. Complete parts(a) through(d).

Age

Males

Females

0-9

10

8

10-19

11

9

20-29

16

16

30-39

20

19

40-49

23

20

50-59

22

22

60-69

18

16

70-79

14

13

(a) Approximate the population mean and standard deviation of age for males.

=

nothing

years

(Round to two decimal places asneeded.)