# Stats Library

## Statistics Assignment Library

1. ##### Solved (Free): A contractor decides to build homes that will include the middle 80% of the market. If the average size of homes built is 1810 square feet
A contractor decides to build homes that will include the middle 80% of the market. If the average size of homes built is 1810 square feet, find the maximum and minimum sizes of the homes the contractor should build. Assume...
2. ##### Solved (Free): A study of drinking and driving has found that 40% of all fatal auto accidents are attributed to drunk drivers
A study of drinking and driving has found that 40% of all fatal auto accidents are attributed to drunk drivers, 2% of all auto accidents are fatal, and drunk drivers are responsible for 20% of all accidents. Find the percentage...
3. ##### Solved (Free): A site is composed of 60% sand and 40% silt in separate layers and pockets. At this site
A site is composed of 60% sand and 40% silt in separate layers and pockets. At this site, 10% of sand samples and 5% of silt samples are contaminated with trace amounts of arsenic. If a soil sample is selected...
4. ##### Solved (Free): If the mean number of cigarettes smoked by pregnant women is 16 and the standard deviation is 8
If the mean number of cigarettes smoked by pregnant women is 16 and the standard deviation is 8, find the probability that in a random sample of 100 pregnant women the mean number of cigarettes smoked will be more than...
5. ##### Solved (Free): ABC Company claims that the proportion of its employees investing in individual investment accounts is higher than national proportion
ABC Company claims that the proportion of its employees investing in individual investment accounts is higher than national proportion of 50%. A survey of 100 employees in ABC Company indicated that 58 of them have invested in an individual investment...
6. ##### Solved (Free): A group of students at a school takes a history test. The distribution is normal with a mean of 25, and a standard deviation of 4
A group of students at a school takes a history test. The distribution is normal with a mean of 25, and a standard deviation of 4. (a) Everyone who scores in the top 30% of the distribution gets a certificate....
7. ##### Solved (Free): Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 250 feet and a standard deviation of 50 feet
Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 250 feet and a standard deviation of 50 feet. A. If X = distance in feet for a fly ball,...
8. ##### Solved (Free): The distribution of systolic and diastolic blood pressure for female diabetes between the ages of 30 and 34 have unknown means
The distribution of systolic and diastolic blood pressure for female diabetes between the ages of 30 and 34 have unknown means. However the standard deviation are $\sigma_s=11.8$ mm Hg and $\sigma_d =9.1$ mm Hg, respectively a) A random sample of...
9. ##### Solved (Free): The following data represents viscosity measurements from a batch chemical process. The data is assumed to be normally distributed
The following data represents viscosity measurements from a batch chemical process. The data is assumed to be normally distributed. The batches are checked for conformance to specification. Batches whose viscosity lies between 84 and 96 are acceptable. A random sample...
10. ##### Solved (Free): Data from the Framingham study allow us to compare the distribution of initial serum cholesterol levels for two population of males
Data from the Framingham study allow us to compare the distribution of initial serum cholesterol levels for two population of males; those who go on to develop coronary artery disease and those who do not. The mean serum cholesterol level...