Most people think of science as being a specific, exact discipline, with a "correct" answer for every problem. Yet you were introduced to the concept of uncertainty in scientific measurements. What is meant by "uncertainty"? How does uncertainty creep into measurements? How is uncertainty indicated in scientific measurements? Can uncertainty ever be completely eliminated in experiments? Explain.

Read "Dinosnur Fossils, in Fine Feather, ShowLink to Birds* by Ann Gibbons (Science, June 26, 1998, vol. 281, p. 2051). Many palcontologists now think that feathers seem to have evolved for what purpose? What arguments do skeptics use to classify the new fossils as belonging to flightless descendants of birds that could fly?

Astronomers use the word detect instead of see because A. no one actually sees the extrasolar planets; they are viewed indirectly. B. the planets are heard through audible radio signals. C. finding planets requires detective work. D. detect is a more formal word suitable for science writing. E. the planets cannot be seen without a telescope.

A student in an exercise science program wishes to study dietary habits of married couples. She surveys married couples from her local gym and asks them (individually) what percent of their daily calories are from fat. She analyzes the results using the Wilcoxon signed-ranks test. Explain why her results are questionable.

Jude is making a poster for his science project. The poster board is $22$ inches wide by $27$ inches tall. He wants to cover two thirds of the area with text or pictures and leave a top margin $3$ times as wide as the side margins and a bottom margin twice as wide as the side margins.

What should be the widths of the margins?

The Latin root -frict- means "to break." A refractory animal is one that "breaks away." The root -fract-*appears in some scientific and mathematical terms, such as fraction. A fraction is a part "broken away" from a larger whole. Explain how the root -fract- contributes to the meaning of below italicized word.
"A fractal is an irregular shape made up of an infinity of irregular parts."

Marie scored 95, 86, and 89 on three science tests. She wants her average score for 6 tests to be at least 90. What inequality can you write to find the average scores that she can get on her next three tests to meet this goal? Use s to represent the lowest average score.

For a science experiment, you would like to use the Doppler effect to double the perceived frequency of a harmonica, from the $261.7-\mathrm{Hz}$ tone (middle $\mathrm{C}$ ) that it emits, to $523.3 \mathrm{~Hz}$ ( $\mathrm{C}_5$ note).Estimate the speed the harmonica must have in order for a stationary observer to hear $523.3 \mathrm{~Hz}$.

During the winter, a horse requires about 36 liters of water per day and a sheep requires about 3.6 liters per day. A farmer is able to supply his horses and sheep with a total of 300 liters of water each day. a. Write an inequality that represents the possible number of each type of animal that the farmer can keep. b.Graph the inequality.

During science class, Sophie measures the temperature of water every minute as it is heating. After a few minutes, the temperature is $82^{\circ} \mathrm{C}$. How far below the boiling point of water is this? A, $8^{\circ} \mathrm{C}$ B. $18^{\circ} \mathrm{C}$ C. $130^{\circ} \mathrm{C}$ D. $191^{\circ} \mathrm{C}$

Physiologists who study warm-blooded animals are interested in the basal metabolic rate, which is one measure of the energy needed for survival. It can be measured from the volume and composition of expired air. In the following table weight $W$, in pounds, of an animal and its basal metabolic rate $B$, in kilocalories per day. ${ }^{28}$ a. Find a formula that models $B$ as a power function of $W$. b. Describe the metabolic weight of a warm-blooded animal to be $W^{0.75}$ if $W$ is its weight in pounds. Direct comparison of food among animals of different sizes is not easy. Clearly, large animals will consume more food than small ones, and to compensate for this, we should take account of the energy needed for survival-that is the basal metabolic rate $B$. To compare the maximum daily food intake among animals of different sizes, we divide this food intake by the metabolic weight.

$$\begin{array}{|l|c|c|} \hline \text { Animal } & \text { Weight } W & \begin{array}{c} \text { Basal metabolic } \\ \text { rate } B \end{array} \\ \hline \text { Rat } & 0.38 & 20.2 \\ \hline \text { Pigeon } & 0.66 & 30.8 \\ \hline \text { Hen } & 4.3 & 106 \\ \hline \text { Dog } & 25.6 & 443 \\ \hline \text { Sheep } & 101 & 1220 \\ \hline \text { Cow } & 855 & 6421 \\ \hline \end{array}$$

Early plants that protected their seeds within cones are called$\rule{1.5cm}{0.4pt}$. These relied on $\rule{1.5cm}{0.4pt}$ to carry their pollen. Later, some plants evolved $\rule{1.5cm}{0.4pt}$ , which attracted animals, particularly $\rule{1.5cm}{0.4pt}$ that carried their pollen. Animal pollination is much more $\rule{1.5cm}{0.4pt}$than wind pollination.

Suppose a wave of negative "animal spirits" overruns the economy, and people become pessimistic about the future. To stabilize aggregate demand, the Fed could$\underline{\phantom{\text{justtextsetekst}}}$ its target for the federal funds rate or Congress could$\underline{\phantom{\text{justtextsetekst}}}$ taxes.

a. increase; increase

b. increase; decrease

c. decrease; increase

d. decrease; decrease

There are originally 255 foxes and 104 rabbits on a particular game reserve. The fox population grows at a rate of 33 foxes per year, and the rabbits increase at a rate of 53 rabbits per year. Under these conditions, how long does it take for the number of rabbits to catch up with the number of foxes? Find how many of each animal will be present at that time.