The following data represent the price (in sen) of 100 grams of red chillies in the local market for 20 consecutive days XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX88 (i) Compute the measurement of central...

The following data represent the price (in sen) of 100 grams of red chillies in the local market for 20 consecutive days. 82 81 80 85 95 83 85 82 77 80 76 74 87 88 85 81 90 92 90 88 (i) Compute the measurement of central tendency. (6 marks) (ii) Compute the variance and standard deviation. (6 marks) (b) The causes for late on different occasions. Causes for Late Arrival Number of Occasions Family problems 8 Had to take the bus 4 Woke up late 20 Bad weather 3 Sick 6 Traffic tied-up 32 Make a pareto chart for these data. (8 marks) Question 2 [20 marks] (a) The probability that boards purchased by a cabinet manufacturer are unusable for building cabinets is 0.15. The cabinet manufacturer bought fifteen boards. Find the probability that (i) none of the fifteen boards are unusable for building cabinets. (3 marks) (ii) at most two of the fifteen boards are unusable for building cabinets. (5 marks) (b) An average of five calls for service per hour are received by a technician. In a randomly selected hour, find the probability that (i) exactly two calls for service will be received. (3 marks) (ii) more than one call for service will be received.


FINAL ASSESSMENT Faculty of Business Course : BBQT2113 Business Statistics Date : 29th April 2021 Time : 9.30am – 12.30pm Duration : 3 hours Module Lecturer : Mr Lee Chee Nian Total marks : 100 marks (worth 50%) Instructions to candidates: 1. Write your name and student number on the front page. 2. Answer questions according to the instruction for each section. 3. Please email to your lecturer within the given time. 4. You may answer these questions either using words format or by scanning your handwritten answer and submit it to your lecturer. Materials allowed for this examination: 1. Non-programmable scientific calculator Student ID : ___________________________________________________ NIRC/Passport No : ___________________________________________________ Program : ___________________________________________________ Date : 29th April 2021 Course : BBQT2113 Business Statistics Page 2 of 7 STRUCTURED QUESTION [Total = 100 marks] Answer ALL questions. Question 1 [20 marks] (a) The following data represent the price (in sen) of 100 grams of red chillies in the local market for 20 consecutive days. 82 81 80 85 95 83 85 82 77 80 76 74 87 88 85 81 90 92 90 88 (i) Compute the measurement of central tendency. (6 marks) (ii) Compute the variance and standard deviation. (6 marks) (b) The causes for late on different occasions. Causes for Late Arrival Number of Occasions Family problems 8 Had to take the bus 4 Woke up late 20 Bad weather 3 Sick 6 Traffic tied-up 32 Make a pareto chart for these data. (8 marks) Question 2 [20 marks] (a) The probability that boards purchased by a cabinet manufacturer are unusable for building cabinets is 0.15. The cabinet manufacturer bought fifteen boards. Find the probability that (i) none of the fifteen boards are unusable for building cabinets. (3 marks) (ii) at most two of the fifteen boards are unusable for building cabinets. (5 marks) (b) An average of five calls for service per hour are received by a technician. In a randomly selected hour, find the probability that (i) exactly two calls for service will be received. (3 marks) (ii) more than one call for service will be received. (5 marks) Date : 29th April 2021 Course : BBQT2113 Business Statistics Page 3 of 7 (c) At a certain community college, the time that is required by students to complete the mathematics competency examination is normally distributed with a mean of 57.8 minutes and a standard deviation of 8 minutes. Find the probability that a student takes between 56 minutes and 1 hour to complete the examination. (4 marks) Question 3 [20 marks] (a) The mean wage for all 5000 employees who work at a large company is RM21.50 per hour and the standard deviation is RM3.50 per hour. Let �̅� be the mean wage per hour for a random sample of certain employees selected from this company. Find the mean and standard deviation of �̅� for a sample size of 150. (3 marks) (b) A sample of 1500 homes sold recently in a state gave the mean price of homes equal to RM344,750. The population standard deviation of the prices of homes in this state is RM63,150. Construct a 99% confidence interval for the mean price of all homes in this state. (7 marks) (c) A random sample of eleven packages was selected from a machine packaging sugar in packages marked 1kg. The actual weights of sugar in kg were: 1.01 1.05 1.03 1.07 0.98 0.99 1.04 1.01 1.05 0.99 1.04 Assuming that the weights are normally distributed, calculate a 95% confidence interval for the mean weight of sugar in packages marked 1kg. (10 marks) Question 4 [20 marks] (a) A teacher claims that students in Accounting class put more hours studying compared to other students. The mean numbers of hour spent studying per week is 25 hours with a standard deviation of 3 hours per week. A sample of 27 Accounting class students was selected at random and the mean number of hours spent studying per week was found to be 26 hours. Determine the teacher’s claim can be accepted at 5% significance level. (9 marks) (b) Iris makes snacks and sell them in a packet of 100g each. Twelve randomly selected packets of snacks are taken and their weights in grams are recorded as follows: 98 102 98 100 96 91 97 97 100 94 101 97 Perform the required hypothesis test at 5% significance level to check whether the mean weight per packet of snack is not equal to 100g. (11 marks) Date : 29th April 2021 Course : BBQT2113 Business Statistics Page 4 of 7 Question 5 [20 marks] The diameter of the longest lichens growing on gravestones were measured. Age of gravestone (years) Diameter of lichen (mm) 9 2 18 3 20 4 31 20 44 22 52 41 53 35 61 22 63 28 63 32 64 35 64 41 114 51 141 52 (a) Construct a linear regression model for the given data. (6 marks) (b) Interpret the relationship between age of gravestone and diameter of lichen. (4 marks) (c) According to your model in part (a), estimate the diameter of lichen given an age of gravestone of 120 years. (3 marks) (d) Obtain the correlation coefficient value. (5 marks) (e) Interpret the value of correlation coefficient. (2 marks) -END OF QUESTIONS- Thank you and good luck! Date : 29th April 2021 Course : BBQT2113 Business Statistics Page 5 of 7 LIST OF FORMULAE or x N x x n  = =   ( ) ( ) 2 2 2 2 or 1 x N x x s n   − = − = −   or fx N fx x n  = =   ( ) ( ) 2 2 2 2 or 1 f x N f x x s n   − = − = −   2 2 or s s = = ( ) ( ) 0 1 mod mod 0 1 0 2 ˆ e e f f x L C f f f f  − = +   − + −   1 2 m m m m n f x L C f −   −  = +        ( ) n x n xxP X x C p q −= = ( ) ! xe P x x  − = x z   − = x x z   − = x = and x n   = x x t s − = y a bx= + SS SS xy xx b = a y bx= − ( ) 2 2SSxx x x n = −   ( ) 2 2SSYY y y n = −   xy xx yy SS r SS SS = ( ) ( )SSxy x y xy n = −    Date : 29th April 2021 Course : BBQT2113 Business Statistics Page 6 of 7 Date : 29th April 2021