In: Statistics and Probability
The following data represent the highest level of education and belief in Heaven for a random sample of adult Americans.
Yes, definitely |
Yes, probably |
No, probably not |
No, definitely not |
Total |
|
Less than high school |
316 |
66 |
21 |
9 |
412 |
High school |
956 |
296 |
122 |
65 |
1439 |
Bachelor’s |
267 |
131 |
62 |
64 |
524 |
Total |
1539 |
493 |
205 |
138 |
2375 |
Construct a relative frequency marginal distribution.
What proportion of adult Americans in the survey definitely believe in Heaven?
Construct a conditional distribution of belief in Heaven by level of education.
Draw a bar graph of the distribution found in part (c).
The given dataset talks about the opinion of Americans on Heaven. Therefore, the dataset is:
Yes, definitely | Yes, probably | No, probably not | No, definitely not | Total | |
Less than high school | 316 | 66 | 21 | 9 | 412 |
High school | 956 | 296 | 122 | 65 | 1439 |
Bachelor’s | 267 | 131 | 62 | 64 | 524 |
Total | 1539 | 493 | 205 | 138 | 2375 |
a) Relative frequency marginal distribution refers to the distribution where each entry is reported as a percentage relative to the grand total. For instance, the relative frequency for Less than high school, yes, definitely is obtained by dividing 316 by 2375.
Hence, the relative frequency marginal distribution for the above the table becomes:
Yes, definitely | Yes, probably | No, probably not | No, definitely not | Total | |
Less than high school | 13.3053 | 2.7789 | 0.8842 | 0.3789 | 17.3474 |
High school | 40.2526 | 12.4632 | 5.1368 | 2.7368 | 60.5895 |
Bachelor’s | 11.2421 | 5.5158 | 2.6105 | 2.6947 | 22.0632 |
Total | 64.8 | 20.7579 | 8.6316 | 5.8105 | 100 |
b) Thus, the proportion of adult Americans in the survey that definitely believe in heaven is the total relative frequency of Yes, definitely column. Hence, this proportion is 64.8%.
c) The conditional distribution refers to the proportions of individuals that belong to a specific category. For instance, the conditional distribution of belief in Heaven by the level of education can be obtained by obtaining the relative frequencies for each row with respect to the total of that row.
Hence, we have conditional frequency distribution as:
Yes, definitely | Yes, probably | No, probably not | No, definitely not | Total | |
Less than high school | 76.699 | 16.0194 | 5.0971 | 2.1845 | 100 |
High school | 66.435 | 20.5698 | 8.4781 | 4.517 | 100 |
Bachelor’s | 50.9542 | 25 | 11.8321 | 12.2137 | 100 |
Total | 64.8 | 20.7579 | 8.6316 | 5.8105 | 100 |
d) We can plot a bar chart for the above chart.