Stats Help for College-level Students

Working with mean, standard deviation and the normal distribution table.

The average weight of an airline passenger's suitcase is 45 pounds. The standard deviation is 2 pounds. If 15% of the suitcases are overweight, find the maximum weight allowed by the airline. Assume the variable is normally distributed.

Calculating the probability that an individual will be within a certain region given the mean and standard deviation.

Assume that the mean systolic blood pressure of normal adults is 120 millimeters of mercury (mm Hg) and the standard deviation is 5.6. Assume the variable is normally distributed. A.) If an individual is selected at random, find the probability that the person's pressure will be between 118 and 121.8mm Hg. B.) If a sample ...continues

Determining if the normal approximation to the binomial distribution should be used.

Determine if the normal approximation to the binomial distribution could be used for the following problems: A.) A study found that 1% of Social Security recipients are too young to vote. 800 Social Security recipients are randomly selected. B.) A study found that 30% of the people in a community use the library in one yea ...continues

Calculating the probability that a mean cost will be less than a specified number given standard deviation.

The average cost of XYZ brand running shoes is $83 per pair, with the standard deviation of $8.00. If 9 pairs of running shoes are selected, find the probability that the mean cost of a pair of shoes will be less than $80. Assume the variable is normally distributed.

Calculating the sample size given a significance level and standard deviation.

A researcher is interested in estimating the average salary of teachers in a large urban school district. She wants to be 95% confident that her estimate is correct. If the standard deviation is $1050, how large a sample is needed to be accurate within $100?

Calculating the true proportion of a group given significance levels and sample size.

A U.S. Travel Data Center survey of 1500 adults found that 42% of respondents stated that they favor historical sites as vacations. Find the 99% confidence interval of the true proportion of adults who favor visiting historical sites as vacations.

Calculating the sample size needed of a true proportion, given significance levels.

A survey of 200 adults showed that 15% played basketball for regular exercise. If a researcher desires to find the 95% confidence interval of the true proportion of adults who play basketball and be within 1% of the true population, how large a sample should be selected?

Working with sampling distribution and probability.

A southern state has an unemployment rate of 6%. The state conducts monthly surveys in order to track the unemployment rate. In a recent month, a random sample of 700 people showed that 35 were unemployed. a) If the true unemployment rate is 6%, describe the sampling distribution of p^. b) Find P(p^ >= 0.05) c) Assum ...continues

Calculate the probability that the sample mean of a variable falls in some range.

At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken What is the probability that the sample mean will be below 0.95 centimeters?

Statistics - Data Models Topic

10) Clearly define the decision variables, the objective function and each constraint. From the Solver Solution, include the value of objective function and each of the decision variables.