40. A regression between foot length (response variable measured in cm) and height (ex- planatory variable measured in inches) for 35 students resulted in the following regres- sion equation: 7 = 10.5 + 0.3x. If we convert the heights of all these 35 students into cm using the conversion factor 1 inch = 2.54 cm and recalculate the regression equation with both the variables measures in cm, what will be the slope of the new regression equation? Choose the closest. (a) . 0.76 n= 35 (b) 0.3 y = 105 + 0.3x (e) 1.94 (d) 0.09 (c) 0.12 41. Researchers at the Universities of Memphis, Alabama at Birmingham, and Tennessee investigated the relationship between insomnia and education status. A random-digit telephone dialing procedure was used to collect data on 575 study participants. In addition to insomnia status (normal sleeper or chronic insomniac), the researchers classified cach participant into one of the four education categories (college graduate, some college, high school graduate, and high school dropout). They measured cach participant's daytime functioning, which is called Fatigue Severity Scale (FSS). The data were analyzed. The result of this study indicated that the fewer years of education, the more likely the person was to have chronic insomnia. Determine the number of treatments for this study. (a) 3 n:525 () Block = c, oc us, had (C) 8 A ImsomALL c, SC his hadCASIO Ex-300ES PLI'S 37. A random variable X has a binomial distribution with n = 8 and p = 0.8. Which of the following statements regarding the probability histogram of X is true? (a) It is skewed to the right. (b) It is symmetric. ne 8 P = 0- 8 ( 6 ) It is skewed to left. (d) It has two modes. (c) none of the other statements is truc 38. A box contains 3 yellow, 2 red, 4 green and 3 black marbles. Two marbles are taken one after the other at random from the box without replacement. What is the probability that both marbles are red? (a) 50 By PA= TZ (b) 2 r 60 (c) 49 (D) 1 3 B 66 18 Total = 12 m P (BIG ) = P(T2 ) P ( # ) (c) P ( # ) = 0- 091 39. The heights of students in some population has a Normal distribution with mean 172 cm. In this population, twenty percent of the students have heights greater than or equal to 178 cm. What is the standard deviation of the heights of the students in this population? 198 Round your answer to the nearest integer. 93 7 cm 213 (b) 8 cm m = 172 (c) 9 cm P ( H > 172 ) *. 2 (d) 10 cm SD = ? (c) None of the other choices gives the correct value to the nearest integer. 1634. A random variable X has the following probability distribution: X 1 2 5 7 Probability 3/ 2k 0.12 0.13 where k is a constant. What is the value of k? (a) 0.10 (b) 0.20 (c) 0.25 0.15 (c) 0.05 35. A rock concert producer has scheduled an outdoor concert. The profit of the concert depends on the weather on that day, whether it is warm, cool, or very cold. If it is warm that day, she expects to make a $25,000 profit. If it is cool that day, she expects to make a $10,000 profit. If it is very cold that day, she expects to suffer a $15,000 loss (i.c. profit of $ -15 000). Based upon historical records, the weather office has estimated the chances of a warm day to be 0.60, chances of a cool day to be 0.25 and the chances of a very cold day to be 0.15. What is the producer's expected profit (i.c. the mean profit)? P ( w ) = 0. 6 (a) $ 11450 D CC ) = 0- 25 (b) $ 15250 P ( VC ) = 0 - 15 (c) $ 19750 (d) $ 6666.67 (c) None of the orther choices gives the correct answer 36. A medical treatment has a success probability of 0.6 (i.c. the probability that the treatment will successfully cure any patient is 0.6). Two patients will be treated with this treatment. Assuming the results are independent for the two patients, what is the probability that neither one of them will be successfully cured? (a) 0.5 (b) 0.04 (c) 0.4 0.16 (c) None of the other choices gives the correct answer 15