STAT177 Assignment #1
Due February 4, 2008
Note: Express all probabilities as decimals accurate to 4 decimals (0.1234) or as percentages accurate to 2 decimals (12.34%) unless otherwise stated. Each question is worth 1 mark unless otherwise stated.
A survey of 40 people tabulated the amount spent last week on groceries. These were the results:
|
176.29 |
170.41 |
253.24 |
36.44 |
65.19 |
309.69 |
191.66 |
179.28 |
|
120.88 |
141.13 |
195.41 |
161.69 |
193.79 |
225.46 |
88.15 |
115.70 |
|
228.07 |
201.73 |
123.62 |
197.37 |
117.93 |
290.14 |
208.56 |
188.63 |
|
131.67 |
188.19 |
66.39 |
61.68 |
210.64 |
164.60 |
225.45 |
170.91 |
|
165.60 |
186.18 |
110.68 |
161.91 |
221.18 |
163.69 |
181.36 |
165.87 |
1) Create a frequency table with a class width of $40.
2) What percentage spent less than $200?
3) What percentage spent at least $120?
4) What percentage spent at least $80 but less than $160?
5) If we remove the outlier, show why the mean is affected more than the median by computing the differences between the old and new values. Summarize your results in a table. (3 marks)
In a particular city, 68% of households own their home and 12% have a line of credit with a financial institution. However, 24.6% of households neither own their home nor have a line of credit.
6) What percentage of the households either own their home or have a line of credit?
7) What percentage of the households who own their home have a line of credit?
8) What percentage of the households who don’t have a line of credit don’t own their home either?
9) What percentage of the households have a line of credit but don’t own their home?
A survey of 500 people was conducted to see if they support certain changes to EI. Those who are employed are divided into those who work full-time and those who work part-time. A third category was created for those who are not employed. Responses were divided into those who support the changes (yes), those who oppose the changes (no) and those who are undecided. These are the results:
|
|
Full-time |
Part-time |
Not
employed |
Total |
|
Yes |
92 |
95 |
38 |
225 |
|
No |
98 |
76 |
12 |
186 |
|
Undecided |
44 |
34 |
11 |
89 |
|
Total |
234 |
205 |
61 |
500 |
10) What percentage overall support the changes?
11) What percentage of those who are employed support the changes?
12) What percentage of those who oppose the bill are not employed?
13) What percentage of those who either oppose the bill or are undecided are employed?
14) Explain why no employment and response categories are mutually exclusive.