The problems are from stat class, 400 level course.

For a number fo years... In the first year after the change, there were 56- survivors in a class of 800. Is this increase explainable as simply sampling variability? Test at a=0.01. Please see attached.

The problems are from stat class, 400 level course.

Let X... We observe X=9 out of n=15. Is the battery more likely to last more t hat 5 years? Please see attached.

A Department store has the following credit terms the finance charge

A Department store has the following credit terms the finance charge. If any is based on the previous balance before payments or credits are deducted. The rates are 1.5% per month up to $1,000 and 1.25% per month on amounts in excess of 1,000. These are annual percentage rates of 18% and 15% respectively. Find the new balance for this account. I need to find the finance charge. Previous balance $991.39 payment $675.00 purchase 96.21 and there is a credit to the account of $84.55 now i need to obtain the new finance charge.

Combination mathematics questions

(See attached file for full problem description and equations) --- Exercise # 1 A) How many nonnegative integer solutions are there to the pair of equations: And B) How many ways are there to distribute 20 toys to m children such that the first two children get the same number of toys if: 1- The toys are identical? 2- The toys are distinct? Exercise #2 A) Prove that: B) What is the value of the sum on each side? C) Show that , m < n --- (See attached file for full problem description and equations)

Suppose that 30 different computer games and 20 different toys are to be distributed among 3 different bags of Christmas presents...

Suppose that 30 different computer games and 20 different toys are to be distributed among 3 different bags of Christmas presents. The first bag is to have 20 of the computer games. The second bag is to have 15 toys. The third bag is to have 15 presents, any mixture of games and toys. How many ways are there to distribute these 50 presents among the 3 bags?