EXAM 2Write your name:___________________ KEY _____________________ (print carefully)Research Methods and Statistics, Fall, 2016PSY 418Teacher: Bob JosephsPractice Exam 21. The relationship between a statistic and a parameter is roughly equivalent to the relationship between ______.a. a typical UT class and all UT students.b. a mean and a standard deviation.c. a parameter and a populationd. descriptive statistics and inferential statistics.2. You are instructed to add 10 points to each score, square the resulting value, and find the sum of the squared numbers. How would this set of instructions be expressed in summation notation? a. ΣX + 102 b. (ΣX + 10)2 c. Σ(X + 10)2 d. ΣX2 – 43. If it is theoretically possible to divide the existing categories of a variable into an infinite number of values, then it is an example of a _____ variable. a. independentb. dependentc. discreted. continuous4. For the following distribution of discrete quiz scores, if a score of X = 4 or higher is needed for a passing grade, how many individuals passed?X f5 64 53 52 31 2a. 3 b. 11 c. 16 d. cannot be determined5. In a distribution with negative skew, scores with the highest frequencies are _____.a. on the right side of the distributionb. on the left side of the distributionc. in the middle of the distributiond. evenly distributed throughout the distribution6. For the distribution of continuous data presented the following table, what is the percentile rank for X = 8.5? X C%9 100%8 80%7 50%6 25%a. X = 90% b. X = 80% c. X = 65% d. X = 50%7. For the distribution of continuous data presented the following table, what is the percentile rank for X = 8.0?X C%9 100%8 80%7 50%6 25%a. X = 90% b. X = 50% c. X = 80% d. X = 65%8. For the scores shown in the following stem and leaf display, what is the lowest score in the distribution?StemLeaf8 3147 9456 70425 684 14a. 0.41b. 40c. 41 d. 41.49. T/F. For the distribution of continuous data shown in the following table, the percentile rank for X = 21 is 39%.X C%25-29 100%20-24 80%15-19 20%a. Trueb. False10. One sample with n = 8 scores has a mean of M = 12, and a second sample with n = 4 scores has a mean of M = 8. If the two samples are combined, what is the mean for the combined set of scores?a. 11.0b. 10.7c. 16.0d. 1011. In a population of N = 60, 59 of the individuals all have scores that are exactly 1 point above the mean. From this information, what can you determine about the score for the sixtieth individual?a. It is also above the mean, but its value cannot be determined from the information given.b. It is below the mean by 59 points.c. It is below the mean, but its value cannot be determined from the information given.d. It is below the mean by 1 point.12. Which of the following statements cannot be true for a distribution of scores?a. 80% of the scores are above the mean. b. 80% of the scores are above the median.c. 80% of the scores are above the mode.d. None of the options are false statements.13. T/F. For a positively skewed distribution, the mean usually has a larger value than either the median or the mode.a. Trueb. False14. T/F. It is possible for the value of the mode to be greater than the value of the mean.a. Trueb. False15. T/F. Adding a new score to a distribution will not change the value of the mean, as long as the new score has the same value as the mean.a. Trueb. False16. What is the value of SS (sum of squared deviations) for the following population?Population: 2, 3, 4, 7a. 14/3b. 14c. 78d. 16/317. A sample of n = 800 scores has SS = 50. If these same exact scores constituted a population with an N=800, then the SS value for the population would be _____.a. 50b. greater than 50c. less than 50d. impossible to determine without additional information18. A sample of n = 225 scores has M = 25 and s2 = 64. What is the sample standard deviation? a. 5b. 64c. √64d. 64÷2519. What position in the distribution corresponds to a z-score of z = -2.00?a. below the mean by 2 pointsb. below the mean by a distance equal to 2 standard deviationsc. more than one may be correctd. below the mean by a distance equal to 2 standard errors of the mean20. For a sample with M = 75 and s = 24, what is the X value corresponding to z = –0.25?a. 80b. 81c. 69d. cannot be determined using the information given21. If a population with μ = 0 and σ = 1.5 is transformed into z-scores, then the distribution of z-scores will have a mean of ___ and a standard deviation of ___.a. 0 and 1b. 0 and 2.25c. 1 and 2.25d. 0 and 1.5 (unchanged)22. Using z-scores, a population with µ = 27 and σ = 3 is standardized so that the new mean is µ = 50 and σ = 10. After the standardization, one individual has a score of X = 55. What was this individual’s score in the original distribution?a. X = 30b. X = 25.55c. X = 28.55d. none of the above23. What z-score value separates the bottom 10% of a normal distribution from the top 90%?a. z = 1.28b. z = 0.01c. z = –1.28d. z = –0.0124. A normal distribution has a mean of µ = 40 with σ = 10. What proportion of the scores in this distribution are smaller than X = 30?a. 0.1587b. -0.1587c. 0.8413d. -0.841325. A normal distribution has a mean of µ = 24 with σ = 5.5. What is the minimum score needed to avoid being in the bottom 14% of the distribution?a. X = >19.27b. X = >18.5c. X = >29.94d. X = >18.0626. John drives to work each morning and the trip takes an average of µ = 25 minutes. The distribution of driving times is normal with a standard deviation of σ = 10 minutes. For a randomly selected morning, what is the probability (in percentages) that John’s drive to work will take no more than 40 minutes but will take more than 36 minutes?a. 7.93%b. 15.26%c. 15.54%d. 6.89%27. For a normal population with a mean of µ = 80 and a standard deviation of σ = 10, what is the probability of obtaining a sample mean greater than M = 75 for a sample of n = 25 scores? a. p = 0.0062b. p = 0.9938 c. p = 0.3085 d. p = 0.691528. Which of the following accurately describes the critical region? a. outcomes with very low probabilities if the null hypothesis is trueb. outcomes with high probabilities if the null hypothesis is truec. outcomes with very low probabilitiesd. outcomes with