Are the marks one receives in a course related to the amount of time spent studying the subject? To investigate this mysterious possibility, a student took a random sample of 10 students who had enrolled in an accounting class last semester. He asked each to report his or her mark in the course and the total number of hours spent studying accounting. These data are listed here: Study

$$\begin{array}{rllllllllll}\text { time } & 40 & 42 & 37 & 47 & 25 & 44 & 41 & 48 & 35 & 28 \\ \text { Marks } & 77 & 63 & 79 & 86 & 51 & 78 & 83 & 90 & 65 & 47\end{array}$$

Calculate the covariance.

In the following paragraph, cross out each Incorrect verb form and write the correct form above it. If all the verbs in a sentence are correct, write C above the sentence.

Example: Railroads in the United States $\overset{\text{began}}{\cancel{\text{begun}}}$ with a few horse-powered lines, in the 1800s.

By the end of the nineteenth century, the United States have five transcontinental lines.

a. What are the three main particles in the modern model of an atom? b. Why do atoms have no electric charge even though most of their particles have charges? c. What is atomic number, and how is it used to distinguish one element from another? d. The atomic number of the isotope nitrogen-15 is 7 . How many protons, neutrons, and electrons make up an atom of nitrogen-15?

In many of the world’s poorest countries, nearly 50 percent of the population is under 15 years of age. If these people are to help improve the productivity of their economies, they must be trained in modern methods of production. In 2000, just over 4 million of the 8.8 million people of Chad were under 15. Explain why it would be difficult for many of these children to be educated and become productive members of a growing economy.

Avoid repetition by replacing the boldfaced word or expression with a synonym from the following words.

$$\begin{array}{lllll}\text { eradicate } & \text { understudy } & \text { ungag } & \text { update } & \text { upheaval } \\ \text { upkeep } & \text { upturn } & \text { withdraw } & \text { withdrawal } & \text { withstand }\end{array}$$

____d Our neighbors have modernized their kitchen. It now has a decidedly modern look.

The United States has a land area of about

$$3,536,278\ mi^2.$$

Illinois has a land area of about

$$57,918\ mi^2.$$

What is the probability that a location in the United States chosen at random is not in Illinois? Give your answer to the nearest tenth of a percent. How can you solve this problem using the complement of an event? How do you write a fraction as a percent?

Are the marks one receives in a course related to the amount of time spent studying the subject? To investigate this mysterious possibility, a student took a random sample of 10 students who had enrolled in an accounting class last semester. He asked each to report his or her mark in the course and the total number of hours spent studying accounting. These data are listed here.

$$\begin{array}{rllllllllll}\text { Study } & & & & & & & & & & \\ \text { time } & 40 & 42 & 37 & 47 & 25 & 44 & 41 & 48 & 35 & 28 \\ \text { Marks } & 77 & 63 & 79 & 86 & 51 & 78 & 83 & 90 & 65 & 47\end{array}$$

Determine the least squares line.

The United States Postal Service delivers about

$$2 ^ { 8 } \cdot 5 ^ { 2 }$$

pieces of mail each second. There are

$$2 ^ { 8 } \cdot 3 ^ { 4 } \cdot 5 ^ { 2 }$$

seconds in 6 days. How many pieces of mail does the United States Postal Service deliver in 6 days? Write your answer as an expression involving powers.

Constructing a rain gutter is a design for a rain gutter.

Express the volume $V$ as a function of $\theta$.

For the underlined phrase or sentence, choose the revision that most improves the writing. A single green tear drops from one eye. $\underline{\text{This poignant design is often reprinted.}}$ A. As a result, this poignant design is often reprinted. B. Because this poignant design beautifully reflects the book's content, it is often reprinted on modern editions. C. Cugat often reprints this poignant design. D. Correct as is

Listed below are nine technical accounting terms:

$$\begin{array}{lll}\text { Variable costs } & \text { Relevant range } & \text { Contribution margin } \\ \text { Break-even point } & \text { Fixed costs } & \text { Semivariable costs } \\ \text { Economies of scale } & \text { Sales mix } & \text { Unit contribution margin }\end{array}$$

Each of the following statements may (or may not) describe one of these technical terms. For each statement, indicate the accounting term described, or answer "None" if the statement does not correctly describe any of the terms.

e. Unit sales price minus variable cost per unit.

Design an experiment that would test the ability of fern gametophytes to grow on different soils.

Design a method to determine the solubility of an unknown substance at $50^{\circ} \mathrm{C}$.

An old manuscript reveals that a landowner in the time of King Arthur held 3.00 acres of plowed land plus a livestock area of 25.0 perches by 4.00 perches. What was the total area in the more modern unit of square meters? Here, 1 acre is an area of 40 perches by 4 perches, 1 rood is an area of 40 perches by 1 perch, and 1 perch is the length 16.5 ft.