Researchers would like to know whether the proportions ofelementary school children who are obese differ in rural and urbanarea. An earlier study found that 50% of urban school children and45% of rural school children are obese. The researchers select 153urban school children and 191 rural school children. Suppose[^(p)]1 and [^(p)]2 denotesample proportions of urban and rural school children respectivelywho are obese.
Answer all the questions below (where appropriate) as afraction not as a percentage.
What is the expected proportion of obese among urban schoolchildren, i.e. expected value of [^(p)]1?[Answer to two decimal places.]
| A: 0.34 | B: 0.43 | C: 0.50 | D: 0.78 | E: 0.97 |
What is the standard deviation of proportion of obese amongurban school children, i.e. σ([^(p)]1)?[Answer to four decimal places.]
| A: 0.0404 | B: 0.1299 | C: 0.1494 | D: 0.3599 | E: 0.8455 |
What is the expected proportion of obese among rural schoolchildren, i.e. expected value of [^(p)]2?[Answer to two decimal places.]
| A: 0.44 | B: 0.45 | C: 0.49 | D: 0.60 | E: 0.98 |
What is the standard deviation of proportion of obese amongrural school children, i.e. σ([^(p)]2)?[Answer to four decimal places.]
| A: 0.0360 | B: 0.1933 | C: 0.4943 | D: 0.5395 | E: 0.8700 |
What is the expected difference of proportions of obese betweenurban and rural school children, i.e. expected value of[^(p)]1 − [^(p)]2?[Answer to two decimal places.]
| A: 0.02 | B: 0.03 | C: 0.05 | D: 0.07 | E: 0.11 |
What is the standard deviation of difference of proportions ofobese between urban and rural school children, i.e.σ([^(p)]1 − [^(p)]2)?[Answer to four decimal places.]
| A: 0.0002 | B: 0.0044 | C: 0.0541 | D: 0.4994 | E: 0.8715 |
What is the probability that the difference of proportions ofobese between urban and rural school children will be larger than0.10? i.e. find P([^(p)]1 −[^(p)]2 > 0.10). [Answer to four decimalplaces.]
| A: 0.0451 | B: 0.1778 | C: 0.2705 | D: 0.3058 | E: 0.3746 |
