Stats Help for College-level Students

Statistics

4.) 20 rivets out 100 in a new box that we tested had break strength below the desired level. Since this is a critical part for assembly, we want to be 99% confident of how many rivets are below the desired level. Calculate the confidence interval of the percentage of rivets that are below the desired level. 5.) We expect a 1 ...continues

Working with combinations.

I have 9 chalkboards to be distributed amongst 4 classrooms. If each class must get at least 1 chalkboard, how many possible divisions can I have?

Statistics

#2 If i am grading the class according to your z score in a normal dist. would you rather have a score of 70 in class A where the mean is 55 and the standard deviation is 10, or a score of 80 in class B where the mean is 60 and sd of 15? What would the percentile rank be in class a@b and what does it mean to you. How would you ...continues

Business Statistics

Finding the number of different combinations.

Business Statistics

Probability Questions

Probability using Binomial Distribution

7) On a very hot summer day, 5% of the production employees at Midland States Steelare absent from work. The production employees are to be selected at random for a special in-depth study on absenteeism.What is the probability of selecting 10 production employee at random on a hot summer day and finding that none of them are abs ...continues

Business Statistics

Probability questions

Probability - Binomial, Combinations

12) If 3% of the electric bulbs manufactured by a company are defective, find the probability that in a sample of 100 bulbs, five are defective 13) Three cards are drawn from a deck of 52 cards without replacement. Find the probability that a) two are jacks and one is king b) all cards are of one unit ...continues

Central limit theorem/Sampling distribution of a sample mean

An SRS of 400 American adults is asked, "What do you think is the most serious problem facing out schools?" Suppose that in fact 30% of all adults would answer "drugs" if asked this question. The proportion X of the sample who answers "drugs" will vary in repeated sampling. In fact, we can assign probabilities to values of X us ...continues

Central limit theorem/sampling distribution of a sample mean

A bottling company uses a filling machine to fill plastic bottles with cola. The bottles are supposed to contain 300 milliliters. In fact, the contents vary according to a normal distribution with mean=298 ml and standard deviation=3 ml. a)What is the probability that an individual bottle contains less than 295 ml? b)What is t ...continues