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The grades of 8 students on an exam were as follows: Student Grade 1 66 2 70 3 64 4 88 5 74 6 72 7 87 8 79     Find the median grade of these 8 students.

The American Journal of Public Health published a study of the relationship between passive smoking and nasal allergies in Japanese female students.  The study revealed that 80% (i.e., p = 0.80) of the students from heavy-smoking families showed signs of nasal allergies on physical examinations.  Consider a sample of 10 Japanese female students exposed daily to heavy smoking in their families.  What is the probability that at least 7 (i.e., 7 or more) of the 10 students will have nasal allergies?

A study is conducted on a group of 9,000 high school students nationwide.  Each week for a period of 43 weeks participants must take an unannounced urine analysis to screen for illegal drug use.  What are the experimental units in this study?

The mean of the starting salary data that we have been using is 28,475 dollars and the standard deviation is 9,369 dollars.  According to the Empirical Rule, we expect 99% of the starting salaries to fall between what two numbers?

A swine producer reads a report stating that the average litter size in the US is 7.8 pigs per litter.  However, he feels that the average litter size on his farm is not 7.8 pigs/litter (he wants to detect departure in either direction from the hypothesized mean of 7.8 pigs/litter).  To test his hypothesis, he reviews his records for the past year and randomly selects 16 litters, which averaged 8.0 pigs/litter.  The standard deviation is 1 pig/litter. Use the appropriate table to find the critical value of the test statistic (use a significance level of α = 0.01).

Breeders of the Longhorn breed of cattle select to increase the length of the horns (i.e., the distance from the tip of one horn to the tip of the other horn).  A Longhorn breeder would like to know the average length of horns found on Longhorn cattle in Texas.  A random sample of 144 Longhorn cattle yields a mean horn length of 72 inches and a standard deviation of 15 inches. Estimate the population mean for length of horns of Longhorn cattle in Texas using a point estimate.

You are interested in purchasing a new car.  One of the many points you wish to consider is the resale value of the car after 5 years of ownership.  Since you are particulary interested in a certain foreign sedan, you decide to estimate the resale value of this car with a 95% confidence interval.  You manage to obtain data on 16 recently resold 5-year-old foreign sedans of that model.  These 16 cars were resold at an average price of $10,000 with a standard deviation of $1,000. Estimate the true mean resale value of this model of foreign car using a 95% confidence interval.  What assumption must be met in order for this confidence interval to be valid?

A college professor wants to estimate the difference in mean test scores of students who have taken his statistics and genetics classes in the past 10 years.  He selects a random sample of 20 student records from the statistics course and a random sample of 22 student records from the genetics course.  These two samples were independent random samples.  The study provided the results shown in the table below.  Calculate the pooled estimate of the variance.   Statistics Genetics Sample size 20 22 Sample mean 78 75 Sample standard dev. 10 12

A random sample of sale prices of homes in Columbus, Ohio yielded the following summary information:      Median = $125,000     Lower quartile = $82,000     Upper quartile = $168,000      Lowest price = $46,000     Highest price = $276,000 Construct a box plot for these data.  Based on this box plot, is the lowest selling price of $46,000 a suspect or highly suspect outlier?

The birth weights of a sample of 8 calves (in pounds) are as follows:   66    70    64    88    74    72    87    79 Calculate the variance of this sample of 8 calf birth weights.