MTH540 – Introduction to Elementary Statistics. DUE: Sunday - 12 August, 2012 NOTE: Please ensure that all stages of the computations are clearly provided to indicate how you arrived at your final...

MTH540 – Introduction to Elementary Statistics.
DUE: Sunday - 12 August, 2012
NOTE: Please ensure that all stages of the computations are clearly provided to indicate how you arrived at your final response.
1.
Identify each of the following statistics as either descriptive or inferential:
a). Seventy-three percent of Italian-American households in the U.S. own a computer.
b). Households with children under the age of 18 are more likely to have access to the Internet(62%) than family households with no children (53 %).
c). Hank Aaron hit 755 career home runs.
d). The average SAT score of incoming college freshmen at a local college was 950.
e). On a recent poll, 67% of Americans had a favorable opinion of the transportation services provided by their local authorities.
Answer:
a) Descriptive Statistics because it is used to describe the group that is being studying.
b) Inferential Statistics because predictions about populations are made from the sample.
c) Inferential statistics because conclusions are made of hitting the home runs.
d) Descriptive Statistics because it summarizes the given data as average.
e) Descriptive Statistics because it describe the percentage of Americans opinion of transportation services.
2.
Classify the following data as nominal, ordinal, interval, or ratio.
Explain your choice.
1. Average monthly temperature in degrees Fahrenheit for the city of Wilmington throughout the year.
2. Average monthly rainfall in inches for the city of Wilmington throughout the year.
3. Performance rating of employees classified as Above Expectations, Meets Expectations, or Below Expectations.
4. Education level of survey respondents:
Level
a. High School
b. Bachelor’s degree
c. Master’s degree
5. Marital status of survey respondents:
Status
a. Single
b. Married
c. Divorced
6. Age of the respondents.
7. Gender of the respondents.
8. The year in which the respondents were born.
9. The voting intentions of the respondents in the survey classified as Republican, Democrat, or Unclassified.
Answer:
1. Ratio scale because the temperature is based on a true zero point.
2.  Interval scale because the monthly rainfall represent fixed measurement units.
3. Ordinal scale because performance ratings are ranked ordered from greatest to least.
4. Ordinal scale because education is ranked ordered from lower to higher level.
5. Nominal because variables are names or labels for characteristics.
6. Ratio because the age of the respondents is based on a true zero point.
7. Nominal because variables are names or labels for characteristics.
8. Interval because the year represent fixed measurement units.
9. Nominal because variables are names or labels for characteristics.
3.
The following table represents the exam grades from 36 students from a certain class I might have taught.
Exam Scores:
60
95
75
84
85
74
81
99
89
58
66
98
99
82
62
86
85
99
79
88
98
72
72
72
75
91
86
81
96
86
78
79
83
85
92
68
a). Construct a Frequency distribution with 9 classes ranging from 56 to 100 from the data above.
b). Construct a relative and cumulative frequency distribution from the data above
c). Construct a stem and leaf diagram from the data above using one stem for the scores in 50s, 60s, 70s, 80s, and 90s.
Solution:
a) Class width = Range/Number of classes
= (100 – 56)/9
= 4.9 ~ 5
Frequency distribution
    Classes
    Frequency
    56 – 61
    2
    61 – 66
    1
    66 – 71
    2
    71 – 76
    6
    76 – 81
    3
    81 – 86
    8
    86 – 91
    5
    91 – 96
    3
    96 – 101
    6
    Total
    36
b)
    Classes
    Frequency
    Relative frequency
    Cumulative...