Study Guide: Fall Mid-Term 2009 AP StatisticsName:
Directions: Work on these sheets. Answer completely, but be concise.
Part 1: Multiple Choice (3 points each).Circle the letter corresponding to the best answer.
Chapter 1
1. You measure the age, marital status and earned income of an SRS of 1463 women. The number and type of variables you have measured is
2. Which of the following is likely to have a mean that is smaller than the median?
Understand a real life example of skewed data.
3. The weights of the male and female students in a class are summarized in the following boxplots:
Be able to interpret the above box plot
4. When testing water for chemical impurities, results are often reported as bdl, that is, below detection limit. The following are the measurements of the amount of lead in a series of water samples taken from inner-city households (ppm).
5, 7, 12, bdl, 10, 8, bdl, 20, 6
Be able to determine mean median of above data
Chapter 2
5.The heights of American men aged 18 to 24 are approximately normally distributed with mean 68 inches and standard deviation 2.5 inches. Half of all young men are shorter than
6.Use the information in the previous problem. Only about 5% of young men have heights outside what range
7.Increasing the frequencies in the tails of a distribution will:
8.The area under the standard normal curve corresponding to –0.3<Z<1.6 is
Chapter 3
9.In a statistics course, a linear regression equation was computed to predict the final exam score from the score on the first test. The equation was y-hat = 10 + .9x where y-hat is the predicted final exam score and x is the score on the first test. Carla scored 95 on the first test. What is the predicted value of her score on the final exam?
10.Refer to the previous problem. On the final exam Carla scored 98. What is the value of her residual?
11.A study of the fuel economy for various automobiles plotted the fuel consumption (in liters of gasoline used per 100 kilometers traveled) vs. speed (in kilometers per hour). A least squares line was fit to the data. Here is the residual plot from this least squares fit.
What does the pattern of the residuals tell you about the linear model?
Chapter 4
12. Suppose we fit the least squares regression line to a set of data. What do we call any individual points with unusually large values of the residuals?
13. The effect of removing the right-most point (near the positive x-axis) in the scatterplot shown would be:
14.If removing an observation from a data set would have a marked change on the position of the LSRL fit to the data, what is the point called:
15.Which of the following statements are correct:
I.Two variables that are strongly associated will have a correlation near 1.
II.Regression requires an explanatory-response relationship, while correlation does not.
III.Even though the correlation between two variables may be high, in order to use the LSRL to predict, there needs to be an explanatory-response relationship between x and y.
Chapter 5
A chemical engineer is designing the production process for a new product. The chemical reaction that produces the product may have a higher or lower yield depending on the temperature and the stirring rate in the vessel in which the reaction takes place. The engineer decides to investigate the effects of combinations of two temperatures (50˚C and 60˚C) and three stirring rates (60 rpm, 90 rpm, and 120 rpm) on the yield of the process. Ten batches of feedstock will be processed at each combination of temperature and stirring rate.
16.What are the experimental units?
17.Identify all factors (explanatory variables).
18.What is the response variable?
19.How many treatments are there?
20.How many experimental units are needed?
Chapter 6
21.An assignment of probability must obey which of the following?
22.A die is loaded so that the number 6 comes up three times as often as any other number. What is the probability of rolling a 1 or a 6?
Questions 23 and 24 relate to the following: In a particular game, a fair die is tossed. If the number of spots showing is either four or five, you win $1. If the number of spots showing is six, you win $4. And if the number of spots showing is one, two, or three, you win nothing. You are going to play the game twice.
23.The probability that you win $4 both times is
24.The probability that you win at least $1 both times is
- Experience has shown that a certain lie detector will show a positive reading (indicates a lie) 10% of the time when a person is telling the truth and 95% of the time when a person is lying. Suppose that a random sample of 5 suspects is subjected to a lie detector test regarding a recent one-person crime. Then the probability of observing no positive reading if all suspects plead innocent and are telling the truth is
Part 2: Free Response
Communicate your thinking clearly and completely.
(10 Points)
26.(a)
Problems based on Chapter 2 requiring knowledge of Normal Curves, Mean, Standard deviation, zscores.
(b)
(15 points)
27.
Problems from Chapter 5 requiring knowledge of how to design a block design experiment.
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