In: Statistics and Probability
When a scientist conducted a genetics experiments with peas, one sample of offspring consisted of 903 peas, with 702 of them having red flowers. If we assume, as the scientist did, that under these circumstances, there is a 3 divided by 4 probability that a pea will have a red flower, we would expect that 677.25 (or about 677) of the peas would have red flowers, so the result of 702 peas with red flowers is more than expected. a. If the scientist's assumed probability is correct, find the probability of getting 702 or more peas with red flowers. b. Is 702 peas with red flowers significantly high? c. What do these results suggest about the scientist's assumption that 3 divided by 4 of peas will have red flowers? a. If the scientist's assumed probability is correct, the probability of getting 702 or more peas with red flowers is nothing. (Round to four decimal places as needed.) b. Is 702 peas with red flowers significantly high? ▼ No, Yes, because the probability of this event is ▼ less greater than the probability cutoff that corresponds to a significant event, which is ▼ 0.95. 0.05. 0.5. c. What do these results suggest about the scientist's assumption that 3 divided by 4 of peas will have red flowers? A. Since the result of 702 peas with red flowers is significantly high, it is not strong evidence against the scientist's assumption that 3 divided by 4 of peas will have red flowers. B. Since the result of 702 peas with red flowers is not significantly high, it is strong evidence against the scientist's assumption that 3 divided by 4 of peas will have red flowers. C. Since the result of 702 peas with red flowers is significantly high, it is strong evidence supporting the scientist's assumption that 3 divided by 4 of peas will have red flowers. D. Since the result of 702 peas with red flowers is not significantly high, it is not strong evidence against the scientist's assumption that 3 divided by 4 of peas will have red flowers. E. The results do not indicate anything about the scientist's assumption. F. Since the result of 702 peas with red flowers is significantly high, it is strong evidence against the scientist's assumption that 3 divided by 4 of peas will have red flowers.
A.
This becomes a case of the binomial distribution with the event of success being that a pea will have a red flower with probability p. Let X be the random variable which denotes the presence of red flowers in n peas.
we know that, p = 3/4
= 0.75
P(X=x) = (nCx)*px*(1-p)n-x
With n = 903 and using the above formula:
P(X702) = 0.030
B.
Definition of an unusual no. of success in a binomial experiment :
If,
P(Xx) < 0.05
and P(Xx) < 0.05 then x is an unusual no. of successes in that experiment.
Since P(X702) = 0.03 < 0.05
then we can say that X = 702 is a significantly high no. given the p and n.
C.
As we can see that 702 successes with p = 0.75 are an unusual no. of success thus probability need to be a bit high so that 702 does not remain a significantly high no. of successes.
Hence we can say that,
Scientist's null hypothesis that p = 0.75 will be rejected and thus,
F. Since the result of 702 peas with red flowers is significantly high, it is strong evidence against the scientist's assumption that 3 divided by 4 of peas will have red flowers.
is the correct answer.
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