Question

1. In 431 NFL football games that went to overtime, the teams that won the coin toss went on to win 235 of those games. If the coin-toss method is fair, we expect that the teams winning the coin would win about 50% of the games, so we expect about 215.5 wins in 431 overtime games. Assuming that there is a0.5 probability of winning a game after winning the coin toss, find the probability of getting at least 235 winning games among the 431 teams that won the coin toss. That is, given n = 431 and p = 0.5, find the probability of at least 235 wins.

1. 0.3803
2. 0.0035
3. 0.9664
4. 0.0336                                                                                  E. None

2. Identify the population: A survey of 500 adults in the U.S. found that 54% drink coffee daily.

1. Collection of the 500 adults surveyed
2. Collection of all adults in the U.S.
3. 54%
4. 500                                                                                        E. None

3. Identify the sample: A survey of 500 adults in the U.S. found that 54% drink coffee daily.

1. Collection of the 500 adults surveyed
2. Collection of all adults in the U.S.
3. 54%
4. 500                                                                                       E. None

4. Identify the data set’s level of measurement: The IQ scores of students in a class.

1. Nominal
2. Ordinal
3. Interval
4. Ratio                                                                                    E. None

5. Identify the data set’s level of measurement: The nationality of each person on an airplane.

1. Nominal
2. Ordinal
3. Interval
4. Ratio                                                                                   E. None

6. Identify the data set’s level of measurement: The salaries of nurses at a hospital.

1. Nominal
2. Ordinal
3. Interval
4. Ratio                                                                                    E. None

7. Decide which method of data collection would be most appropriate: A study of the effect of using MyStatLab (as an application tool) on grades in a statistics course.

1. Observational study
2. Experiment
3. Simulation
4. Survey                                                                                  E. None

Answer 1

In 431 NFL football games that went to overtime, the teams that won the coin toss went on to win 235 of those games. If the coin-toss method is fair, we expect that the teams winning the coin would win about 50% of the games, so we expect about 215.5 wins in 431 overtime games. Assuming that there is a0.5 probability of winning a game after winning the coin toss, find the probability of getting at least 235 winning games among the 431 teams that won the coin toss. That is, given n = 431 and p = 0.5, find the probability of at least 235 wins.

correct answer D. 0.0336

Mean = np= 431*0.5=215.5

standard deviation = sqrt(npq)=sqrt(431*0.5*0.5)=10.38027

We want the probability of at least 235 wins, so x = 235.

Z value=(x-mean)/standard deviation = (235-215.5)/10.38027 = 1.83

The probability is 0.0336 (Ref Z-Table) for the coin flip winning team to win at least 235 games.

Identify the population: A survey of 500 adults in the U.S. found that 54% drink coffee daily.

correct answer B. Collection of all adults in the U.S.

Identify the sample: A survey of 500 adults in the U.S. found that 54% drink coffee daily.

correct answer A.Collection of the 500 adults surveyed

Identify the data set’s level of measurement: The IQ scores of students in a class.

correct answer C. Interval