Question
how do you solve 17?
In Exercises 15-18, refer to the accompanying table, Genetics. which describes results from groups of 10 births from 10 different Girls x sets of parents. The random variable x represents the number of girls among 10 children. Number of P(x) 0 0.001 0,010 0.044 15. Mean and Standard Deviation Find the mean and standard 3. an deviation for the numbers of girls in 10 births. m16. Range Rule of Thumb for Unusual Events Use the range80 205 0.205 0.246 couse rule of thumb to identify a range of values containing the usual numbers of girls in 10 births. Based on the result, is 1 girl in 10 births an unusually low number of girls? Explain. 8 0.044 0.010 0.001 17, tsing Probabilities for Unusual Events ind the probability of getting exactly 8 girls in 10 births. b. Find the probability of getting 8 or more girls in 10 births. to c. Which probability is relevant for determining whether 8 is an unusually high number of girls in 10 births: the result from part (a) or part (b)? d. Is 8 an unusually high number of girls in 10 births? Why or why not? 18/Using Probabilities for Unusual Events a. Find the probability of getting exactly 1 girl in 10 births. 1D b. Find the probability ofgetting l or fewer girls in 10 births. c. Which probability is relevant for determining whether 1 is an unusually low number of
Explanation / Answer
Q.17)
a) Probability of getting exactly 8 girls in 10 births is 0.044
i.e. P(x = 8) = 0.044
b) Probability of getting 8 or more girls in 10 births,
i.e P(X >=8) = P(x = 8) + P(x = 9) + P(x = 10)
= 0.044 + 0.010 + 0.001
P(X >= 8) = 0.055
c) The results from part b) is relevent for determining whether 8 is an unusually high number of girls in 10 births.
An outcome is unusually high if it is in the upper tail of the distribution - i.e., if the probability of getting it or a higher value is small.
d) here P(x >=8) = 0.055 is greater than 0.05
Thus, 8 is not an unusually high number of girls in 10 births.
Note: if any event with probability less than 0.05 is an unusual event otherwise it is usual event.
