Stats Help for College-level Students

Jjoint probability distribution

suppose that x and y have the following joint probability distribution X 2 4 _______________________________________________ 1 0.10 0.15 Y 3 0.2 0.3 5 .1 .15 Find the marginal distribution of x a ...continues

Statistic qustion about adequate sampling

I have an xbar of 1000 and an Sx of 103. I have a random sample of 30. I am trying to figure out if this is an adequate sample without knowing the total population in an office. Can you lead me to a useable equation?

Simple statistical excell functions/formulas

Please DO NOT respond if you're UNABLE to give detailed and specific answer to both question. Let's say I have two columns of numbers (5 in each column). 1/ Pls. advise of the following functions' FORMULA in excell: percentile range rank weighted average confidence correlation forecast 2/ and elaborate as to WHAT ...continues

Chebyshev's theorem - standard deviation

A scientific calculator operates on the average 5.3 hour before needing a recharge. According to Chebyshev's theorem, if the operating times have a standard deviation of 0.6 hour. A. Between what 2 values will at least 75% of the operating times fall? B. At least what percentage of the operating times will fall in the interval ...continues

Cconfusing probability problem

I already took stats and now I am taking this random math course in which the professor is trying to make probability allot harder than it is. Please help . Please explain why in a two card hand out of a deck of 52 cards the probability of getting 2 consecutive cards is 208/1326, how did you get this?

Understanding Statistics - using the formulas when working on examples

As a Bachelor of Business student studying Statistics as one of my cor subjects and have found that I am having real trouble with understanding the problems we face in class. I have tried hard to get it without luck..... I have attached three examples.. and as my text book is too complex I am looking for another way to g ...continues

Statistics Problem

1. Bill has completed a ten question multiple choice test on which he answered seven questions correctly. Each question had one correct answer to be chosen from four alternatives. Bill says that he answered the test by randomly selecting the answers without reading the questions or answers. a. What is the expected number of ...continues

Stats Problem

1. A group of day to day workers can work either 0 hours, eight hours or 12 hours at a pay rate of $9.75 per hour. (The 12 hour day pays regular time for the first eight hours and double time for the remaining four hours.) On any given day there is a 0.2 probability of not working at all, 0.7 probability of working an eight ho ...continues

Stats Problem

1. The camera department of a large department store sells three different brands of cameras: Proxima, Yakima, and Tetron. Approximately 60% of the cameras sold are Yakimas with Tetrons accounting for 30% of sales and Proxima the remaining 10%. Store records show that approximately ¼ of those who purchase a Yakima return with ...continues

statistics problem

The lengths of adult earthworms are normal with mean 8.6cm. and standard deviation 1.6cm. 40 adult earthworms are chosen at random. Approximate the probability that at lease 18 of them are less than 4.5cm.long.