The Mayoral challenger claims that less than 30% of residents over the age of 25 have bachelor's degrees in our city. To test this claim, you survey 80 adults over the age of 25 and find only 18 possess bachelor's degrees. At the 5% level of significance, is there enough evidence to support the challengers claim?

A friend of yours tells you that they heard that 65% of all college athletes end up losing a finger or toe in their college athletic career.  You're highly skeptical of this, but your not sure if that percentage is an over exageration or an under exageration.  You survey 101 former student-athletes and find that 60 of them lost a digit during their college athletic career.  Is this enough evidence to conclude that the true percentage of student-athletes that lose a digit during their collegiate career is really different from 65%?

1. The percentage of 12- to 17-year-olds who reported talking at least once in the past year with their parents about the dangers of drug, tobacco, or alcohol is 60% nationally. A state youth council believes this proportion is higher in their state, where there has been an intense media campaign about this issue. A survey of randomly chosen students from across the state shows 1032 of 1642 students reporting they are having these conversations with their parents. Is there evidence that the percent of students using drugs, tobacco or alcohol in this state is above the national rate?

According the the U.S. Census bureau, the percentage of Santa Ana residents with a bachelor's degree or higher is 14% and the percentage of Irvine residents with a bachelor's degree or higher is 68.5%. Suppose that the sample sizes were 1000 for the Santa Ana group and 1000 for the irvine group. Is there enough evidence to conclude that people who live in Irvine have a higher level of education compared to people living in Santa Ana?

It is believed that 11% of all Americans are left-handed. A college needs to know how many left-handed desks to place in the big lecture halls being constructed on its campus. In a random sample of 210 students from that college, whether or not a student was left-handed was recorded for each student. The college wants to know if the data provide enough evidence to show that students at this college have a different percentage of left-handers than the general American population? State the random variable, population parameter, and hypotheses. State the Type I and Type II errors in the context of this problem.a) The symbol for the random variable involved in this problem is               The wording for the random variable in context is as follows:          b) The symbol for the parameter involved in this problem is               The wording for the parameter in context is as follows:          c) Fill in the correct null and alternative hypotheses:     H0:H0:                    HA:HA:…

There is a 75% chance that those who are called will serve on jury duty.  If 12 people are called for jury duty, what is the probabilty that none of the people will serve on the jury?

A medical school claims that more than 28% of its students plan to go into general practice. It is found that among a random sample of 130 of the school's students, 39% of them plan to go into general practice. You wish to conduct a significance test to evaluate the school's claim.

USA Today ran a report about a UNC poll of 1248 adults from the southern U.S. It was reported that 8% of those surveyed believe that Elvis Presley still lives. The article began with the claim that "almost 1 out of 10" Southerners still thinks Elvis is alive. At the 0.01 significance level, test the claim that the true percentage is 10%.

It is believed that 11% of all Americans are left-handed. A college needs to know how many left-handed desks to place in the big lecture halls being constructed on its campus. In a random sample of 210 students from that college, whether or not a student was left-handed was recorded for each student. The college wants to know if the data provide enough evidence to show that students at this college have a higher percentage of left-handers than the general American population? State the random variable, population parameter, and hypotheses. State the Type I and Type II errors in the context of this problem.

An art authenticator has a history of successfully identifying forgeries. Over her career, she has been asked to evaluate 74 actual forgeries and correctly identified 69 of them. Further, among all the authentic art she has looked at, she has never claimed any to be forgeries. An art dealer is considering purchasing a painting but is worried it is a fake. His experience in the field over the years indicates about 3% of the artwork he comes across is forged. a) If the dealer employs the services of the authenticator, and she indicates the painting is genuine, what is the chance it is actually a forgery? b) Without authentication, the dealer can sell the painting for $20,000. The price would increase to $25,000 if the painting were authenticated as genuine, but obviously it is worthless if it is deemed a forgery. The authenticator charges $2,000 for her services. Do you think it is worth it for the dealer to use the authenticator? Why or why not?