At the moment, OHaganBooks.com is selling 1,000 books per week and its sales are rising at a rate of 200 books per week. Also, it is now selling all its books for $20 each, but its price is dropping at a rate of$1 per week. a. At what rate is OHaganBooks.com’s weekly revenue rising or falling? b. John O’Hagan would like to see the company’s weekly revenue increase at a rate of $5,000 per week. At what rate would sales have to have been increasing to accomplish that goal, assuming all the other information is as given above?

Simplify each expression. (Hint: Multiply before adding or subtracting.)

$$- 3 \left[ \begin{array} { r r r } { 4.2 } & { - 7.3 } & { 0.7 } \\ { 2.7 } & { - 9.3 } & { 11.8 } \\ { 3.6 } & { 8.2 } & { - 4.8 } \end{array} \right] - 2 \left[ \begin{array} { c c c } { 7.8 } & { - 4.1 } & { 9.4 } \\ { - 8 } & { 0 } & { 0.8 } \\ { - 1.4 } & { 5.9 } & { 3.3 } \end{array} \right]$$

Irene is buying new carpet for her rectangular family room. The room is 15 ft wide and 24 ft long. The carpeting is sold only in square meters. How many square meters of carpeting will she need? Round your answer to the nearest tenth of a square meter.

Factor the polynomial.

$$3 z ^ { 2 } - 27$$

Make an appropriate u-substitution, and then use the Endpaper Integral Table to evaluate the integral.

$$\int \cos \sqrt { x } d x$$

What does correlation tell you about the relationship between two variables?

Write the negation of each statement. The lunch was served at noon.

If $\mathbf{F}(x, y)=P(x, y) \mathbf{i}+Q(x, y) \mathbf{j}$ is a vector field in a domain D with div F = 0 and curl F = 0, then the complex function $g(z)=P(x, y)+i Q(x, y)$ is analytic in D. _____

Find the exact value of each expression.

$$\sin \frac { 3 \pi } { 8 }$$

Complete the square and factor the resulting perfect square trinomial.

$$x ^ { 2 } + 24 x$$

Whitney deposits $9,000 for two years. She compares two different banks. State Bank will pay her 4.1% interest, compounded monthly. Kings Savings will pay her 4.01% interest, compounded continuously. How much interest does State Bank pay?

A humor piece published in the British Medical Journal ("Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomized control trials," Gordon, Smith, and Pell, BMJ, 2003:327) notes that we can't tell for sure whether parachutes are safe and effective because there has never been a properly randomized, double-blind, placebo-controlled study of parachute effectiveness in skydiving. (Yes, this is the sort of thing statisticians find funny . ... ) Suppose you were designing such a study: How would you randomize this "experiment"? How would you make the experiment double-blind?

Suppose that f is a continuous additive function on

$$\mathbb{R}.$$

If c := f (1), show that we have f(x) = cx for all

$$x \in \mathbb{R}.$$

An office employs six customer service repres entatives. Each day, two of them are randomly selected and their customer interactions are monitored for the purposes of improving customer relations. In how many ways can the repres entatives be chosen?