T1.pdf

BENG 2143 ENGINEERING STATISTICS

TUTORIAL: 1 DATA DESCRIPTION 1. The following data represent the number of robberies in 2005. Types of crime

a) b) c) d) e)

Number of Offences (in 000) Bank 12 Gas station 12 Street or highway 224 Convenience store 32 residence 56 Commercial house 64 Construct a relative frequency distribution. What a percentage of robberies were of a gas station? Construct a frequency bar graph. Construct a relative frequency bar graph. Construct a pie chart.

2. The following data represent the number of live multiple delivery births in 2001 for women aged 15-49 years old. Age Number of multiple births 15 – 19 66 20 – 24 411 25 – 29 1653 30 - 34 2926 35 - 39 1813 40 - 44 356 45 - 49 96 a) Find the mean and standard deviation age. b) Draw a frequency histogram for the data to verify that the data are bell shaped.

3. If P(A) = 0.6, P(B) = 0.3 and P(A∩ B) = 0.05 , determine the following probabilities: (a) P(A') (b) P(A ∪ B) (c) P(A'∩B) (d) P(A ∩ B') (e) P[(A ∪ B)'] (f) P(A'∪ B)

4. One bag contains 8 white and 9 black marbles. A second bag contains 11 white, 10 black and 12 green marbles. If 1 marble is selected at random from each bag, find the probability that (a) all marbles are black. (b) neither marbles are white. (c) there are 2 marbles with different colours. 5. Suppose that in an assembly of 500 defective computers, it is found that 230 are due to overload, 245 are due to software problem, 208 are due to hardware problem, 132 are due to overload and software problems, 67 are due to hardware and software problems, 75 are due to overload and hardware problems and 45 defective computers are due to all 3 problems. If a defective computer is selected at random from this assembly, find the probability that this computer is defective due to: (a) overload but not due to software problems. (b) overload and hardware problems but not due to software problems. (c) neither software nor hardware problems.