Math Answers

The mean monthly sale of a particular household item in department stores was observed as 133.3 units per store. After an advertising campaign, data on sales of this item from 25 stores were collected and it is found that the mean sales have increased to 141.5 units with a standard deviation of 15.2 units. Was the advertising campaign successful? Assume that level of significance is 5%.

A basket contains 10 ripe and 4 unripe bananas. If three bananas are taken from the basket one after the other, determine the possible values of the random variable U representing the number of unripe bananas

From the past experience of software quality testing, it is known that the probability of the presence of an error in coding is 0.05. If the probability of a tester detecting an error when the error is present is 0.78 and the probability of incorrectly detecting an error when the error is present is 0.78 and the probability of incorrectly detecting an error when the error is not present is 0.06 (a) What is the probability that a code is tested as having an error? (b) What is the probability that a code tested as having an error when the error is present?

prove that xcosecx=1+(x)^2/6+(7/360)*x^4

 The Super Discount store (open 24 hours a day, every day) sells 8-packs of paper towels, at the rate of approximately 420 packs per week. Because the towels are so bulky, the annual cost to carry them in inventory is estimated at $.50. The cost to place an order for more is $20 and it takes four days for an order to arrive.

a. Find the optimal order quantity.

b. What is the reorder point?

c. How often should an order be placed? 

Find the dependency of vector (1,0,3),(0,1,2),(2,3,1),(4,1,0)

The variance of the number of cars sold per day is 2.27 what is the Standard deviation of the cars per day?

Construct a probability distribution table if we let X the random variable be the number of

boys in the family with 3 children.

The differential equation which has y 4 = Cx3 − 3 as its general solution is:

If $51.30 interest is earned in two years on a deposit of $95, then what is the simple annual interest rate?