Execute these steps.

a. State the hypotheses and identify the claim. b. Find the critical value(s). c. Compute the test value. d. Make the decision. e. Summarize the results.

Employ the traditional method of hypothesis testing unless otherwise specified.

The percentages of adults 25 years of age and older who have completed 4 or more years of college are $23.6 \%$ for females and $27.8 \%$ for males. A random sample of women and men who were 25 years old or older was surveyed with these results. Estimate the true difference in proportions with $95 \%$ confidence, and compare your interval with the Almanac statistics.

	Women	Men
Sample size	350	400
No. who completed 4 or more years	100	115

Consider the initial-value problem $y^{\prime}=2 y, y(0)=1$. The analytic solution is $y(x)=e^{2 x}$.

Approximate y (O. l) using one step and the RK4 method.

Match the term with its definition.

$$\begin{matrix} \text{Definition} & \text{Term}\\ \text{The removal of soil by water or wind} & \text{A. aquaculture}\\ \text{ } & \text{B. ozone layer}\\ \text{ } & \text{C. ecological footprint}\\ \text{ } & \text{D. monoculture}\\ \text{ } & \text{E. biological magnification}\\ \text{ } & \text{F. ecological hot spot}\\ \text{ } & \text{G. global warming}\\ \text{ } & \text{H. desertification}\\ \text{ } & \text{I. biodiversity}\\ \text{ } & \text{J. erosion}\\ \end{matrix}$$

The annual sales (in billions of dollars) of global positioning system (GPS) equipment from the year 2000(x=0) through 2006 are given in the following table:

a. Find an equation of the least-squares line for these data.

b. Use the equation found in part (a) to estimate the annual sales of GPS equipment for 2008, assuming that the trend continued.

In 1998, as an advertising campaign, the Nabisco Company announced a "1000 Chips Challenge," claiming that every 18-ounce bag of their Chips Ahoy! cookies contained at least 1000 chocolate chips. Dedicated Statistics students at the Air Force Academy (no kidding) purchased some randomly selected bags of cookies, and counted the chocolate chips. Some of their data are given below.

$$\begin{array}{lllllllll}1219 & 1214 & 1087 & 1200 & 1419 & 1121 & 1325 & 1345 \\ 1244 & 1258 & 1356 & 1132 & 1191 & 1270 & 1295 & 1135\end{array}$$

a) Check the assumptions and conditions for inference. b) Create a 95% confidence interval for the average number of chips in bags of Chips Ahoy! cookies. c) Interpret your interval in this context.

The Bureau of Labor Statistics reports a $6.0 \%$ unemployment rate for Americans whose maximum attained a level of education is a high school diploma. Is the unemployment rate significantly different for Americans who have earned their bachelor's degrees? Suppose we have a random sample of 500 Americans whose maximum attained a level of education is a bachelor's degree and found 18 who are unemployed. Use these sample results to conduct a hypothesis test to determine whether the unemployment rate for Americans whose maximum attained a level of education is a bachelor's degree differs significantly from the unemployment rate for Americans whose maximum attained level of education is a high school diploma.

a. State the appropriate hypotheses for your significance test.

Match the term with its definition.

$$\begin{matrix} \text{Definition} & \text{Term}\\ \text{A rise in Earth's average temperature} & \text{A. aquaculture}\\ \text{ } & \text{B. ozone layer}\\ \text{ } & \text{C. ecological footprint}\\ \text{ } & \text{D. monoculture}\\ \text{ } & \text{E. biological magnification}\\ \text{ } & \text{F. ecological hot spot}\\ \text{ } & \text{G. global warming}\\ \text{ } & \text{H. desertification}\\ \text{ } & \text{I. biodiversity}\\ \text{ } & \text{J. erosion}\\ \end{matrix}$$

University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rates. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents.

$$\begin{array}{c|cccccccc} \hline x & 12.5 & 30.0 & 24.5 & 14.3 & 7.5 & 27.7 & 16.2 & 20.1 \\ \hline y & 26 & 73 & 39 & 23 & 15 & 30 & 15 & 25 \\ \hline \end{array}$$

Would you say the correlation is low, moderate, or high? positive or negative?

Products "Made in the USA." Refer to Exercise $2.154$ (p. 119) and the Journal of Global Business (Spring 2002) survey to determine what "Made in the USA" means to consumers. Recall that 106 shoppers at a shopping mall in Muncie, Indiana, responded to the question, "Made in the USA" means what percentage of U.S. labor and materials?" Sixty-four shoppers answered, "100%." Estimate the true proportion of consumers who believe "Made in the USA" means $100 \%$ U.S. Explain what the phrase " $90 \%$ confidence" means for this interval.

Color and clarity of diamonds. Diamonds are categorized according to the "four C's": carats, clarity, color, and cut. Each diamond stone that is sold on the open market is provided a certificate by an independent diamond assessor that lists these characteristics. Data for 308 diamonds were extracted from Singapore's Business Times (Journal of Statistics Education, Vol. 9, No. 1, 2001). Color is classified as $\mathrm{D}, \mathrm{E}, \mathrm{F}, \mathrm{G}, \mathrm{H}$, or I, while clarity is classified as IF, VVS1, VVS2, VS1, or VS2. In addition to color and clarity, the independent certification group (GIA, HRD, or IGI), the number of carats and the asking price were recorded. Find and interpret the median of the data set.

As a special promotion for its 20-ounce bottles of soda, a soft drink company printed a message on the inside of each bottle cap. Some of the caps said, "Please try again!" while others said, "You're a winner!" The company advertised the promotion with the slogan "1 in 6 wins a prize." Grayson's statistics class wonders if the company's claim holds true at a nearby convenience store. To find out, all 30 students in the class go to the store and each buys one 20-ounce bottle of the soda. Two of the students in Grayson's class got caps that say, "You're a winner!" Does this result give convincing evidence that the company's 1-in-6 claim is false?

The Navstar Global Positioning System (GPS) utilizes a group of 24 satellites orbiting the Earth. Using "triangulation" and signals transmitted by these satellites, the position of a receiver on the Earth can be determined to within an accuracy of a few centimetres. The satellite orbits are distributed evenly around the Earth, with four satellites in each of six orbits, allowing continuous navigational "fixes." The satellites orbit at an altitude of approximately $11,000$ nautical miles [$1$ nautical mile $=$ $1.852 \mathrm{~km}=6076 \mathrm{~ft}]$.Find the speed of each satellite.

Choose the best answer. It has been projected that aquaculture could supply about one-half the global demand for seafood by 2025. However, future production through aquaculture could be limited because (a) concentrated waste from aquaculture facilities contaminates rivers and oceans. (b) raising fish in a protected environment could lead to a fish population overshoot. (c) the economies of developing countries would be negatively affected. (d) ocean fishing operations would go out of business.

Budget lapsing at army hospitals. Accountants use the term budget lapsing to describe the situation that occurs when unspent funds do not carry over from one budgeting period to the next. Due to budget lapsing, U.S. army hospitals tend to stockpile pharmaceuticals and other supplies toward the end of the fiscal year, leading to a spike in expenditures. This phenomenon was investigated in the Journal of Management Accounting Research (Vol. 19, 2007). Data on expenses per full-time equivalent employees for a sample of 1,751 army hospitals yielded the following summary statistics: $\bar{x}=\$ 6,563$, $m=\$ 6,232, s=\$ 2,484, Q_{\mathrm{L}}=\$ 5,309$, and $Q_{\mathrm{U}}=\$ 7,216$. Interpret, practically, the measures of relative standing.