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An electric utility company has found out that the weekly number of occurrences of lightning striking the
transformers is a Poisson distribution with mean 0.4.
Required:
i) The probability that no transformer will be struck in a week.
ii) The probability that at most two transformers will be struck in a week.
Date posted:
December 7, 2018
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In a certain factory that employs 500 men, 2% of all employees have a minor accident in a given year. Of
these, 30% had safety instructions whereas 80% of all employees had no safety instructions.
Required:
Find the probability of an employee being accident-free given that he had:
i) no safety instructions.
ii) safety instructions
Date posted:
December 7, 2018
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State clearly what is meant by two events being statistically independent.
Date posted:
December 7, 2018
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A firm has four plants scattered around the city producing the same homogeneous item at all plants. The first plant produces 30 per cent of the total production, second plant 25 per cent, third plant 35 per cent and the fourth plant 10 per cent. The firm has a single warehouse in the city for storing the finished product of all the plants without any distinction. From the past performance records on the proportion of defectives, it has been found that 5 per cent, 10 per cent, 15 per cent and 20 per cent from the items produced at plants 1, 2, 3, and 4 respectively are defective. Before the shipment of the items to a dealer, one unit is selected and found defective. What is the probability that the item was produced in plant 3?
Date posted:
December 7, 2018
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A firm recently submitted a bid for a turnkey project for a 500 MW power plant. If its main competitor submits a bid, the chances of bid being awarded to the firm is 0.3. If the main competitor doesn't bid, there is a
3/4 chance of the firm getting the contract. There is a 0.50 chance that the main competitor will bid.
i) What is the probability of the firm‟s getting the contract?
ii) What is the probability that the competitor‟s bid given that the firm's bid is awarded?
Date posted:
December 7, 2018
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Computer analysis of satellite data has correctly forecast locations of economic oil deposits 80% of the time.
The last 24 oil wells drilled produced only 8 wells that were economic. The latest analysis indicates economic quantities at a particular location. What is the probability that the well will produce economic quantities of oil?
Date posted:
December 7, 2018
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The following table gives a bi-variate frequency distribution of 50 managers according to their age and salary
(in rupees).
If a manager is chosen at random from the above distribution, find the chance that;
(i) he is in the age group of 30-40 and earns more than Rs.1500,
(ii) his earnings are in the range of Rs.2000-2500 and is less than 50 years old.
Date posted:
December 7, 2018
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Three groups of children contain respectively 3 girls and 1 boy; 2 girls and 2 boys; 1 girl and 3 boys. One child is selected at random from each group, show that the chance that the three selected, consist of 1 girl and 2 boys is 13/32.
Date posted:
December 7, 2018
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A problem is given to three managers A, B, C whose chances of solving are ½, ⅓, ¼ respectively. What is the probability that the problem will be solved?
Date posted:
December 7, 2018
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Moving averages are often used in an effort to identify movements in share prices. Approximate monthly
closing prices (in Sh. per share) for Toys Children Ltd. for December 2000 through November 2001 are
shown below:
Date posted:
December 6, 2018
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The table below reports the annual net salary amounts for an accountant who began employment with an
auditing firm in 1995. In addition, the values of the Consumer Price Index (CPI) for 1995 through 1999 is
shown.
Required:
Determine whether there is a difference in percentage salary increase between 1995 and 1999 in terms of
stated (current) shillings amounts and in terms of constant (deflated salary, using CPI) shillings.
Date posted:
December 6, 2018
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"The standard deviation is the natural partner to the mean". Explain.
Date posted:
December 6, 2018
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Why is the mode not used extensively in statistical analysis?
Date posted:
December 6, 2018
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Describe briefly how to estimate the median on a grouped frequency distribution graphically.
Date posted:
December 6, 2018
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In what situation would a weighted mean be used?
Date posted:
December 6, 2018
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A machine produces circular bolts and, as a quality control test, 250 bolts were selected randomly and
the diameter of their heads measured as follows:
Required:
Determine whether the customer is getting reasonable value if the label on the circular bolt advertises
that the average diameter of the head is 0.97642 cm.
Date posted:
December 6, 2018
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The table below shows the income per month of borrowers and the percentage of all mortgages as
provided by Building Society Mortgages in the year 2000.
Required:
i) Calculate some suitable measures of central tendency and dispersion and comment on your results.
ii) Explain with an example the value of descriptive statistics in the accounting function.
Date posted:
December 6, 2018
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What are some of the limitations of index numbers?
Date posted:
December 6, 2018
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Explain some of the uses of index numbers.
Date posted:
December 6, 2018
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The index of industrial production in the Utopia country by July 2001 is given below:
Required:
i) Calculate the index of industrial production for all industries and manufacturing industries.
ii) Comment on your results.
Date posted:
December 6, 2018
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(a) Given the following input – output matrix and demand vector of shoes S, rubber R and glue G industries,
determine the production vector.
(b) If in (a) above the demand of industries changes as follows:
S decreases by 10 units
R increases by 5 units C
increases by 10 units.
What should be the production levels?
Date posted:
December 6, 2018
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Drumstick Chicken Wings Ltd supplies chicken wings for Kuku Inn with the following demand and cost
functions for a given week:
P = 100 – 0.01 x - Price
TC = 50x + 30,000 - Total cost
Where:
x – number of chicken wings supplied.
Required:
i) Total revenue for Drumstick Chicken Wings Ltd.
ii) Determine the number of chicken wings that maximize weekly profit.
iii) What is the difference in profit if the Drumstick Chicken Wings Ltd. objective is to maximize revenue rather than profit?
Date posted:
December 6, 2018
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Explain the following terms as used in calculus:
i) Turning point.
ii) Second order derivative condition.
iii) Partial derivative.
iv) Mixed partial derivative.
v) Saddle point.
Date posted:
December 6, 2018
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On the study of costs and revenue for production of biro pens by a small company ACO Ltd, the
following expressions were determined. Before production starts a set-up cost of Sh.1500 existed.
AR = 600 – 0.5q Average revenue
MC = 140 – 8q + 0.15q2 Marginal cost
Required:
i) The expression for profit.
ii) At what quantity q is profit maximized.
iii) Is this quantity q also the point that revenue is maximized?
Date posted:
December 6, 2018
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Two firms A and B in Nairobi Industrial area make glue. The cost functions for making glue for the two
firms are as follows:
Firm A - C = 0.2x + 200
Firm B - C = 0.6x + 50
Where x – is litres of glue produced in „000?.
Required:
By drawing a graph of these functions, show whose firm?s costs increase more rapidly.
Date posted:
December 6, 2018
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A company employs four classes of machine operators (A,B,C,D): all new employees are hired as class D
and, through a system of promotion, may work up to a higher class. Currently, there are 200 class D, 150
class C, 90 class B and 60 class A employees. The company has signed an agreement with the union
specifying that 20 percent of all employees in each class be promoted, one class in each year. Statistics show that each year 25 percent of the class D employees are separated from the company by reason such as retirement, resignation and death. Similarly 15 percent of class C, 10 percent of class B and 5 percent of class A employees are also separated. For each employee lost, the company hires a new class D employee.
Required:
i) The transition matrix.
ii) The number of employees in each class two years after the agreement with the union.
iii) The equilibrium state in number of employees.
Date posted:
December 6, 2018
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Define the following terms as used in Markovian analysis:
i) Transition matrix.
ii) Initial Probability vector
iii) Equilibrium
iv) Absorbing state
Date posted:
December 6, 2018
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An electronics firm carries out a small-scale test launch of a new low-priced pocket calculator. It estimates from this test that if it went into full-scale production it would sell between 1,000 and 2,500 calculators per month, and that its monthly revenue in thousands of shillings over this range of sales could be represented by the equation:
R = - x2 + 5x
Where: x is the monthly output in thousands of calculators (it is assumed that it sells its entire output).
From experience of calculator production, the firm estimates its marginal cost in thousands of shillings
could be represented by the equation:
MC = x2– x + 2
and that its fixed costs will be Sh.500 per month.
Required:
i) Determine the average cost and revenue equations for this firm.
ii) Determine the profit-maximizing output, the price that should be charged to maximize profit, and how
much each calculator will then cost to make.
Date posted:
December 6, 2018
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The number of shoppers queuing at any given time in a certain supermarket in downtown Nairobi can be
approximately represented by the equation:
Required:
i) The management wants to know when they should deploy more cashiers and the number queuing at
that time.
ii) Determine the number of man-hours spent per day by shoppers queuing.
Date posted:
December 6, 2018
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XYZ Company Limited invests in a particular project and it has been estimated that after X months of
running, the cumulative profit (Sh.„000‟) from the project is given by the function 10x-x2-5,
where x represents time in months. The project can run for eleven months at most.
Required:
i) Determine the initial cost of the project.
ii) Calculate the break-even time in months for the project.
iii) Determine the best time to end the project.
iv) Determine the total profit within the break-even points
Date posted:
December 6, 2018