Stats Help for College-level Students

Phstat clarification

Please solve these problems by using Excel's add-in called PhStat. What this means is that if you have the add-in, you use it (in excel) for the calculations and then cut n paste them into word. If you DON'T have it, you can download and install it from here: http://www.sunflowerlabs.com/phstat If you have trouble install ...continues

Testing a claim using confidence levels.

A computer store claimed that about 80% of all service calls are due to a malfunctioning processor. A sample of 100 service calls is randomly selected and it is found that 70 are due to malfunctioning of processors. Determine the 99% confidence interval for the true proportion of all service calls that are due to the malfunction ...continues

Testing a claim.

A man sells chickens to a restaurant chain. He claims that the mean weight of the chickens is 4 pounds. At a significance level of 0.05 shall we reject the vendors claim? Set up the hypothesis test in standard form and then carry out the test.

Testing a claim in regards to a mean weight using a confidence level.

A flour manufacturer packs flour into paper bags, each of which is supposed to hold 10 pounds, or 160 ounces. Some customers have complained that the bags hold only 9.5 pounds, or 152 ounces. A test is conducted to determine whether the complaint is warranted. The weight of each bag is normally distributed with a Population Stan ...continues

Understanding the types of a hypothesis test.

A Hot Fudge Sundae has on average 12 ounces of ice cream. If I were to set up a hypothesis test to test the ability of a new employee making the hot fudge sundae with an average of 12 ounces of ice cream, would the hypothesis test be a "one tailed" or a "two tailed" test? Briefly Explain.

Working with confidence levels.

I randomly selected 200 likely voters and created a 95 percent confidence interval for the true proportion of voters that will vote for my candidate. My confidence interval has endpoints of 0.39 and 0.45. Given the confidence interval that I created, is my candidate going to win? After constructing the confidence interval I call ...continues

Working with hypothesis tests.

If when you do a Hypothesis test about the Population Mean, somehow you have the actual value for the Population Standard Deviation. Suppose that you were able to get a sample of size 100, and did not know the Population Standard Deviation. What can you do to still carry out the Hypothesis test?

Testing a claim using a mean weight, standard deviation and confidence levels.

A vendor sells turkeys to a restaurant chain. He claims that the mean weight of the turkeys is more than 15 pounds. A sample of 16 turkeys yields a mean of weight of 14 pounds and a standard deviation of 4 pounds. At a significance level of 0.05 shall we reject the vendor's claim? Set up the Hypothesis test in "standard form" an ...continues

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