Stats Help for College-level Students

Standard deviation

Please use MINITAB to solve or explain how I can use MINITAB to solve. 7. Assume that the midterm's scores X are normally distributed. Let X have a mean of 72 and a standard deviation of 12. Then answer the following three questions: a. What is the probability of obtaining a score at least 90? b. What is the probabil ...continues

Probability - probability tree

6. I am thinking about buying a used car. To make an informed decision, I look up the records of used cars in an auto magazine, and find that, unfortunately, 30% have defective transmissions. To get more information on the particular used car, I hire a mechanic who can make a guess on the basis of a quick drive around the block. ...continues

Probability

In Washington, DC, 30% of the families have a MasterCard, 20% have an American Express card, and 25% have a Visa card. 8% of the families have both a MasterCard and an American Express card. 12% have both a Visa card and a MasterCard. 6% have both an American Express card and a Visa Card. a. What is the probability of selectin ...continues

Frequency Distribution - Histogram

The Air Transport Association of America published figures on the busiest airports in the United States. The following frequency distribution has been constructed from these figures for the year 2000. NUMBER OF PASSENGERS ARRIVING AND DEPARTING (MILLIONS) NUMBER OF AIRPORTS 20 - under 30 8 30 - under 40 ...continues

Probability - expected number and the standard deviation

The following data are the result of a historical study of the number of flaws found in a porcelain cup produced by a manufacturing firm. Use these data and the associated probabilities to compute the expected number and the standard deviation of flaws. Flaws Probability 0 0.461 1 0.285 2 0.129 3 0 ...continues

Binomial distribution

Suppose that 72% of a certain population of drivers regularly use seat belts. You take a simple random sample of 15 of these drivers. What is the probability that the number regularly using seat belts is a) more than 10 b) at least 11 c) 7 or more

Formulating a hypothesis and classifying the type of error.

A manufacturer of stereo systems has a production line that produces an average of 100 stereo systems per day. Because of new government regulations, a new safety device has been installed, which the manufacturer believes will reduce average daily output. A sample of 49 days output after the installation of the safety device y ...continues

Stats tests

I am looking for the appropriate statistical test(s) to run on some data. I am trying to find out whether there is any significant differences in 2 groups of people (full-time workers and part-time workers) who all took a customer service survey. The survey scores the person on 8 subscales of customer service, plus on ...continues

Calculating the probability using mean and standard deviation.

The weights of medium oranges packaged by an orchard are normally distributed with a mean of 14 ounces and a standard deviation of 2 ounces. The weights of large oranges are normally distributed with a mean of 18 ounces and a standard deviation of 3 ounces. If we select, at random, one each of the medium and large oranges, det ...continues

Working with time series in multiple regression.

What method has been used to transform Model 1 to Model 2? Equations for Model 1 and Model 2 are as follows: Model 1 Ct = 26.19 + 0.6428GNPt - 0.4398Dt + et Model 2 Ct /GNPt = 25.92(1/GNPt)- 0.4598(Dt/GNPt)+ et C represents Consumption expenditures GNP represents Gross National Product D represents defense spen ...continues