Math Answers

4. The mean breaking strength of the cables supplied by a manufacturer is 1850 with a SD of 100. By a new technique in the manufacturing process, it is claimed that the breaking strength of the cable has increased. To test this claim, a sample of 50 cables is tested and it is found that the mean breaking strength is 1875. Can we support the claim at 1% LOS?

The annual rainfall in San Francisco is approximately normal with mean 22 inches and

standard deviation 7.9 inches. What is the probability that the rainfall in San Francisco

in the next year will be between 20 inches and 30 inches?

 If the random variable X takes the values 1, 2, 3 and 4 such that

P(X = 1) = 3P(X = 2) = P(X = 3) = 5P(X = 4), find the probability distribution and

cumulative distribution function of X.

What is the area of the tail region of the t-distribution with 12 degrees of freedom that falls below the t-value -2.179?

Suppose you are given the side lengths of a right angle triangle, which length is the length of the hypotenuse. How do you know?

A cylindrical silo has a height of 15.5 meters and a diameter of 4.2 meters if 1 can of paint covers 10 square meters how many cans must be bought to paint the curved face with one coat

When do we add the two corresponding areas of the z-score?

Determine whether the vector (9,0,9) is a linear combination of the vectors

(1,1,0), (1,0,1), (2,1,1) and (0,1, −1).

Let f(x)= x^2/x^2-9

(a) Find the intervals where f is increasing and decreasing. Identify the relative

extrema.

(b) Find the intervals where f is concave up and down and identify any inflection points.

(c) Sketch a graph of f using the information from this problem

A. Using the t-table, give the confidence coefficients for each of the following.

1.n=9, 95% confidence

2. n=11, 95% confidence

3. n=24, 95% confidence

4.n=21, 95% confidence

5. n=21, 99% confidence