91Ó°ÊÓ

Suppose you guess on a true-or-false test. Use a tree diagram to find each probability. \(P(4 \text { correct in } 4 \text { guesses })\)

Suppose you guess on a true-or-false test. Use a tree diagram to find each probability. \(P(3 \text { correct in } 4 \text { guesses })\)

Sketch a normal curve for each distribution. Label the \(x\) -axis values at one, two, and three standard deviations from the mean. mean \(=45,\) standard deviation \(=10\)

Find the probability of \(x\) successes in \(n\) trials for the given probability of success \(p\) on each trial. $$ x=3, n=8, p=0.3 $$

Suppose you roll two number cubes. Graph the probability distribution for each sample space. {both numbers even, both numbers odd, one number even and the other odd}

Make a tree diagram based on the survey results below. Then find \(P(\text { a female }\) respondent is left-handed) and \(P(\text { a respondent is both male and right-handed). }\) \(\bullet\) Of all the respondents, 17\(\%\) are male. \(\bullet\) Of the male respondents, 33\(\%\) are left-handed. \(\bullet\) Of female respondents, 90\(\%\) are right-handed.

A football team has a 70\(\%\) chance of winning when it doesn't snow, but only a 40\(\%\) chance of winning when it snows. Suppose there is a 50\(\%\) chance of snow. Make a tree diagram to find the probability that the team will win.

Track To qualify as a contestant in a race, a runner has to be in the fastest 16\(\%\) of all applicants. The running times are normally distributed, with a mean of 63 \(\mathrm{min}\) and a standard deviation of 4 min. To the nearest minute, what is the qualifying time for the race?

Another measure of variation is variance, which equals \(\sigma^{2} .\) Find the variance and the standard deviation of each data set. $$ 60 \mathrm{m} 40 \mathrm{m} \quad 35 \mathrm{m} 45 \mathrm{m} 39 \mathrm{m} $$

Genetics About 11\(\%\) of the general population is left-handed. At a school with an average class size of \(30,\) each classroom contains four left-handed desks. Does this seem adequate? Justify your answer.