Math Answers

Find the inverse function of (x+1)/x

An educational researcher found that the average entrance core of the incoming freshmen in a university is 84. A random sample of 24 students from a public school was then selected and found out that their average score in the entrance exam is 88 with a standard deviation of 16. Is there any evidence to show that the sample students from public school performed better than the rest in the entrance examination using the 0.01 level of significance?

Find the area of region y =17x²/16, y = 9x²/4 and y = 1 - 4x, satisfying x ≤0.

Find the mean of the set 7 10 14 17 20 of data and construct a sampling distribution by selecting 3 samples at a time

Define a set of which both {1, 3, 4} and {0, 3, 5} are subsets. Find such a set with the smallest possible number of elements.

We form the union of a set with 5 elements and a set with 9 elements. Which of the following numbers can we get as the cardinality of the union: 4, 6, 9, 10, 14, 20?

What is the number of subsets of a set with n elements, containing a given element (when element becomes fixed, part of every subset)?

What is the probability that the shelf life of the

battery is between 500 and 550 days?

1.      Find the range, the standard deviation, and the variance for the given samples. Round noninteger results to the nearest tenth.

       a. 1, 2, 5, 7, 8, 19, 22

       b. 3, 4, 7, 11, 12, 12, 15, 16

       c. 2.1, 3.0, 1.9, 1.5, 4.8

       d. 5.2, 11.7, 19.1, 3.7, 8.2, 16.3

       e. 48, 91, 87, 93, 59, 68, 92, 100, 81

Suppose the amount of a popular sport drink in bottles leaving the filling machine has a normal distribution with mean 101.5 milliliters (mL) and standard deviation 1.6. If 36 bottles are randomly selected, find the probability that the mean content is less than 102.1 mL