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Unformatted text preview: Classwork 3 (Chapters 6 8: Chapters 7) Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. For the given event, state whether the difference between what occurred and what you would have expected by chance is
statistically significant or not statistically significant.
1) In 36 rolls of two six—sided dice, the numbers on the dice add to 2 twelve times. 1)
A) statistically significant B) not statistically significant Interpret the level of statistical significance for the event described.
2) A study of 600 college students taking Statistics 101 revealed that 58 students received the grade of 2)
A. Typically 10% of the class gets an A. The difference between this group of students and the
expected value is not significant at the 0.05 level. What does this mean in this case?
A) The probability that the difference occurred due to chance is less than 0.05.
B) The probability of getting an A is 10% and only 9% got an A in this study. The difference is
less than 5% so it is not significant.
C) There is not enough information to make any conclusion.
D) The probability that the difference occurred due to chance is more than 0.05. Find the indicated probability.
3) If you ﬂip a coin three times, the possible outcomes are HHH, HHT, HTH, HTT, THH, THT, TTH, 3)
TTT. What is the probability of getting at least one head? A) g— B) if C) l 1
Z D)2 Determine the probability of the giVen opposite event.
4) The probability that Luis will pass his statistics test is 0.63. Find the probability that he will fail his 4) statistics test.
A) 0.37 B) 1.70 C) 1.59 D) 0.32 Find the expected value. 5) In a game, you have a £5 probability of winning $116 and a 3—:— probability of losing $7. What is 5) your expected value?
A) —$6.84 B) $2.58 C) $9.42 D) ~$4.27 State whether you believe the two variables are correlated. If you believe they are correlated, state whether the
correlation is positive or negative.
6) Rate of pedaling a bicycle and speed of the bicycle 6)
A) Positive correlation B) Negative correlation C) Not correlated Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.
7) A) 0.5 B) —0.9 C) 0.9 D) 0.5 SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Solve the problem.
8) The following table gives the total sales (revenue) and profits for 8 retailers. Construct a 8)
scatter diagram for the data and state whether sales and profits for these companies have
no correlation, a positive correlation, or a negative correlation. Total Sales Profits «E “4‘0 Company (Millions of $) (Millions of $) at“ 3.5 Adams 9.5 0.5 .8 3.0 Browns 22.0 1.4 “5 25
m Clay 35.0 1.8 g 2 ﬂ
Donners 64.0 3.0 a Esters 27.5 0.9 E 15 Framer 45.0 2.6 ‘3 1.0 Gillies 15.0 ' 0.8 ‘5 0.5 Ha s 57.0 2.2 E14 c. D 20 4:0 60 80 Total Sales. {millions of dollars.) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. State whether there is no correlation, a positive correlation, or a negative correlation between the x and y variables. If
there is a correlation, state whether it is most likely due to coincidence, a common underlying cause, or a direct cause. 9) 9) For a group of students in a statistics class, the scatter diagram compares their test scores (y) and
the number of red shirts they have(x). A) Negative correlation; direct cause B) Negative correlation; coincidence C) No correlation D) Negative correlation; common underlying cause Provide an appropriate response.
10) Estimate the coordinates of the outlier on the graph. 10) 20 15 A) (17, 9) B) (17, 4) C) (9, 17) D) (4,17) Select the bestfit line for the data on the scatter diagram. If none of the lines fit the data, write "none of the lines".
11) Select the best— fit line on the scatter diagram below. 11) A) A B) C
C) B _ D) none of the lines Solve the problem. Round your answers to the nearest whole percent.
12) 12) The scatter diagram shows the data for the prices of a stock (y) and US. employment (x). The .
correlation coefficient r is 0.8. Determine how much of the variation in the stock price can be
accounted for by the best fit line. A) 64% B) 36% C) 20% D) 80% Answer the question using the value of r and the given best—fit line on the scatter diagram.
13) 13) D 2 4 6 8 1D The scatter diagram and best—fit line show the data for the price of a stock (y) and U.S. employment
(x). The correlation coefficient r is 0.8. Predict the stock price for an employment value of 5. A) 7 B) No valid prediction is possible. C) 5.9 D) 4.9 14) 14) El 2 4 B 8 10 The scatter diagram and best—fit line Show the data for the price of a stock (y) and US. employment
(x). The correlation coefficient r is 0.8. Predict the stock price for an employment value of 10.
A) 9.5 B) 8.5 C) 8 D) No valid prediction is possible. ...
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 Spring '08
 MOODY
 Statistics

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