A pathologist has been studying the frequency of bacterial colonies within the field of a microscope using samples of throat cultures from healthy adults. Long-term history indicates that there is an average of 2.98 bacteria colonies per field. Let r be a random variable that represents the number of
A pathologist has been studying the frequency of bacterial colonies within the field of a microscope using samples of throat cultures from healthy adults. Long-term history indicates that there is an average of 2.98 bacteria colonies per field. Let r be a random variable that represents the number of bacteria colonies per field. Let O represent the number of observed bacteria colonies per field for throat cultures from healthy adults. A random sample of 100 healthy adults gave the following information.
| r | 0 | 1 | 2 | 3 | 4 | 5 or more |
| O | 13 | 13 | 27 | 18 | 21 | 8 |
| e−??r |
| r! |
| P(0) | = |
| P(1) | = |
| P(2) | = |
| P(3) | = |
| P(4) | = |
| P(5 or more) | = |
Compute the expected number of colonies E = 100P(r) for r = 0, 1, 2, 3, 4, and 5 or more. (Round your answers to one decimal place.)
| E(0) | = |
| E(1) | = |
| E(2) | = |
| E(3) | = |
| E(4) | = |
| E(5 or more) | = |
Compute the sample statistic
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and the degrees of freedom. (Round your test statistic to three decimal places.)
| d.f. | = |
| ?2 | = |
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