Statistics and Probability Quiz

On a standardized test, Johnny received a score of 85, which was exactly 3 standard deviations above the mean. If the standard deviation for the test is 6, which is the mean for this test?

• 61

• 67

• 73

• 79

Ethan owns a barber shop in town. The average price a customer pays for his service is $50 with a standard deviation of $5. Which percent best represents the probability that any one customer pays between $45 and $72 for his service?

• 68%

• 75%

• 84%

• 95%

In anatomy, pulse rates in adult women are roughly Normal and have a mean of 62 beats per minute and standard deviation of 6 beats per minute. Which choice correctly describes how to find the proportion of women who have a pulse rate greater than 68?

• Find the probability of being below z=1.

• Find the probability of being above z=1.

• Find the probability of being below z=−1.

• Find the probability of being above z=−1.

Human weight is roughly Normal. A group of 10 year old boys are normally distributed with a mean of 62 pounds and a standard deviation of 10 pounds. What is the z-score for a 10 year old boy who weights 58 pounds?

• z=+0.4 (above the mean)

• z=−0.4 (below the mean)

• z=+4.0 (above the mean)

• z=−4.0 (below the mean)

The weights of one-year-old babies at a pediatric clinic are modeled with a normal distribution with a mean of 9.0 kilograms and a standard deviation of 1.3 kilograms. Approximately what percentage of one-year-old babies weigh more than 8.65 kilograms?

• 27%

• 39%

• 61%

• 73%

A marine biologist is doing research at local zoos that house a specific species of turtle. Their weight is normally distributed with a mean of 1000 pounds and a standard deviation of 233 pounds. Approximately what percentage of turtles weigh between 632 pounds and 1210 pounds?

• 57%

• 68%

• 76%

• 84%

Which day had the most unusual profit at Burger Queen, and why? (Your answer needs to refer to the z-score, remember z-score is "where" the data is located)

• Monday, because the z-score is +1.0

• Tuesday, because the z-score is -1.0

• Thursday, because the z-score is +2.0

• Friday, because the z-score is -3.0

Was Friday a good profit day or bad profit day at Burger Queen and why?

• Good, because the profit was above average (because the z score is positive)

• Bad, because the profit was below average (because the z score is negative)

• Good, because the z-score was too close to the average

• Bad, because the z-score is above the mean

In a survey of 600 adults at a theme park, 241 said they planned to buy a refillable drink cup. The attendance at the park for some random day was 4,540. Classify the following numbers as parameter, sample, or statistic.

600 is a _______

241 out of 600 is a ______

4,540 is a _______

Which of the following is correct?

• Parameter, Sample, Statistic

• Sample, Statistic, Parameter

• Statistic, Parameter, Sample

• Sample, Parameter, Statistic

Which method would be the best way to conduct an observational study to determine the effects of vitamin C for preventing cold?

• Randomly assign people to two groups, give one group vitamin C and the other a placebo, and compare results.

• Survey a group of people about their vitamin C intake and track how often they get colds over time.

• Give everyone in a study group vitamin C and compare their results to the general population.

• Ask people if they believe vitamin C prevents colds and record their opinions.