Statistics and Probability Answers

Let A represent the event that someone lives with ASD and B represent the event that someone does not live with ASD. Question 23 Which of the following statements is correct? (1) P.A and B/ D P.A/ P.B/: (2) P.AjB/ D P.A/: (3) P.B/ 6D P.A C/: (4) Events A and B are mutually exclusive. (5) Events A and B are independent. Question 24 Suppose further that P.A/ D 0:96 and P.B/ D 0:04. P.A or B/ D? (1) 0:92: (2) 0:0384: (3) 1: (4) 0:96: (5) 0:04:

Number if people 108 44 206 85 57 Question 21 Which of the following statements is correct? (1) The median is 85 and equals the mean. (2) The value of Q1 is 57. (3) The position of Q2 is 2. (4) The value of Q3 is 157. (5) The distribution of the number of people living with ASD is symmetric. Question 22 The interquartile range is __________________? (1) Equals to the range. (2) Always less than the range. (3) 149: (4) 51: (5) 0:

Number if people 108 44 206 85 57 Question 18 Which one of the following statements is incorrect? (1) The mean and the median are equal. (2) The mean is less than the median. (3) The mode is zero. (4) There is no mode. (5) None of the above. Question 19 What is the sample standard deviation? (1) 64:25: (2) 57:46: (3) 4127:50: (4) 3302: (5) None of the above. 21 Question 20 The coefficient of variation is: (1) 64:25%. (2) 57:46%. (3) 4127:50%. (4) 3302%. (5) 100%.

Age at diagnosis in months 18.5 22 20 30.5 25 Question 15 Which one of the following descriptive statistics is not a measure of central tendency or location? (1) Mean. (2) Median. (3) Mode. (4) Range. (5) All the above measures describe central tendency or location. Question 16 Which one of the following statements is correct with regard to the coefficient of variation? (1) It is a measure of location. (2) It is the difference between the largest and smallest value in a dataset. (3) It is the sample standard deviation squared (4) It is the sample standard deviation expressed as a percentage of the mean. (5) It is the mean squared.

A study reports that 5% of adults are afraid to be home alone at night. If 20 people are randomly selected, what is the probability at least 3 of them are afraid to be home alone at night ? a) Is the situation Binomial or Hypergeometric ? b) How do you know which one it is c) Change the situation so that it could be calculated using other distribution ( for example , if it is binomial , change to hypergeometric )

What criteria are required when using the following distributions? Give a clear example of each - Uniform - Binomial - Hypergeometric

A game consists of rolling a die. If you roll a 1 or 2 you win $5 . If you roll a 4,5, or 6 you pay $1.25 a) Determine the probability distribution for the winnings b ) Determine the expected winnings c) is this a fair game ?

TYPE OF ASD No of people A 108 B 44 C 206 D 85 E 57 Question 13 Which one of the following statements is incorrect? 1. The total number of people living with ASD is 500. 2. The frequency of people living with type B ASD is 0:09. 3. The relative frequency of people living with type C ASD is 0:41. 4. The frequency of people living with type D ASD is 85. 5. None of the above.

TYPE OF ASD No of people A 108 B 44 C 206 D 85 E 57 Question 11 Table above is referred to as a ___? (1) Frequency distribution. (2) Relative frequency. (3) Frequency. (4) Cumulative frequency. (5) None of the above. Question 12 What is the appropriate graphical form to summarise the data in Table above? (1) Scatter plot. (2) Stem-and-leave diagram. (3) Bar or pie chart. (4) Histogram. (5) All of the above plots are appropriate.

Question 9 Consider statements A to D below. (A) Data can be summarised using both tabular and graphical methods. (B) Classes in a frequency distribution are non-overlapping. (C) Frequency refers to the proportion of items in a class while relative frequency refers to the actual count per class. (D) The modal class is the class with the highest frequency. Which statement(s) are incorrect? (1) Only D. (2) Only B. (3) Only C. (4) Only A and B. (5) Only B, C and D. Question 10 The sum of relative frequencies for all class will always equal? (1) 1: (2) 100: (3) The number of classes. (4) The sample size. (5) The total frequency