Bias is a non-sampling error (error occurring during the process of gathering data) that is systematic and deprives a statistical result of its representativeness. It is cumulative as the sample size increases rather than balancing out like random errors.
Ways that bias is introduced include:
-Deliberate selection based on personal judgment of what is representative
- Having substitute members or units that are convenient rather than because of difficulty in making contact with given units.
- Failure to cover the whole of the selected sample like when some people do not answer questioners
- Haphazard selection by human beings rather than being random
- Inadequate, hasty, incomplete and misleading interviewing.
Sampling bias is tolerated in some investigations. Unbiased sample is one that is free from selection and
procedural bias
Wilfykil answered the question on February 20, 2019 at 11:42
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A performance test was done before and after training on 12 persons appointed in clerical positions in a cement factory warehouse in Athi River. Marks...
(Solved)
A performance test was done before and after training on 12 persons appointed in clerical positions in a cement factory warehouse in Athi River. Marks were awarded on a 10-point scale as follows
Did the training improve performance?
Date posted:
February 20, 2019
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Answers (1)
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Write short notes on the following:
i) Uniform distribution
ii) Poisson distribution
iii) Normal distribution
iv) Beta distribution
v) t-distribution
(Solved)
Write short notes on the following:
i) Uniform distribution
ii) Poisson distribution
iii) Normal distribution
iv) Beta distribution
v) t-distribution
Date posted:
February 20, 2019
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Answers (1)
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A major bank BKR Ltd calculates the credit ratings of its credit card customers on a monthly basis. The ratings are poor, good and excellent...
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A major bank BKR Ltd calculates the credit ratings of its credit card customers on a monthly basis. The ratings are poor, good and excellent depending on the payment history. The following matrix shows how the customers change from one category to the other in one month.
Required:
i) Interpret the elements 0.84, 0.2, 0.18 and 0.16. (4 marks)
ii) Given that in August 2003, from customer base of 100,000 the accountswere classified as
Poor 30,000
Good 50,000
Excellent 20,000
What is expected in October?
Date posted:
February 20, 2019
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Answers (1)
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A Markov process describes the movement among the different states of a system as a function of time. Give the various steps in using a...
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A Markov process describes the movement among the different states of a system as a function of time. Give the various steps in using a Markov process for determining a state at (t + 2) and steady state two periods after given state.
Date posted:
February 20, 2019
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Answers (1)
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The total cost function and demand function of Migoya Construction company (MCC) are as follows:
(Solved)
The total cost function and demand function of Migoya Construction company (MCC) are as follows:
Required:
i) Write down the expression of average cost per unit and graph it for x values between x=0 and x=8.
ii) Write the expression for total revenue.
iii) If total revenue is to be maximized, what is the price to be charged?
v) What is the price that maximizes profit?
Date posted:
February 20, 2019
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Answers (1)
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How does differential calculus assist managers in their optimization problems when faced with single variables?
(Solved)
How does differential calculus assist managers in their optimization problems when faced with single variables?
Date posted:
February 20, 2019
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Answers (1)
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MMK Ltd. plans to conduct a survey. The following table shows the tasks involved, the immediately preceding tasks and for each activity duration the most...
(Solved)
MMK Ltd. plans to conduct a survey. The following table shows the tasks involved, the immediately preceding tasks and for each activity duration the most likely estimate (L), the optimistic estimate (O) and the pessimistic estimate (P).
Required:
a) Compute the mean duration and standard deviation for each task
b) The project is budgeted to cost Sh.500,000. Actual costs per day are Sh.10,000. By first identifying the critical path from drawing a network diagram can the project be implemented within the budget.
c) What is the probability of finishing the project 4 days earlier than the expected duration?
Date posted:
February 20, 2019
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Answers (1)
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Sikoka health club specializes in provision of sports/exercise and medical/dietary advice to clients. The service is provided on residential basis and clients reside for whatever...
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Sikoka health club specializes in provision of sports/exercise and medical/dietary advice to clients. The service is provided on residential basis and clients reside for whatever number of days that suit their needs. Budget estimates for the year ending 30 June 2003 is as follows:
Required:
i) Summary of budgeted contribution to be earned by Sikoka Health Club for the year ended 30 June 2003 for each of the nine possible outcomes.
ii) State the client fee strategy that will result from the use of the maximax, maximin and minimax regret decision criteria.
Date posted:
February 20, 2019
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Answers (1)
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What is Laplace criterion? How does it differ from Hurwicz criterion?
(Solved)
What is Laplace criterion? How does it differ from Hurwicz criterion?
Date posted:
February 20, 2019
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Answers (1)
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A fruit/juice kiosk along Lusaka road, VegFresh kiosk has come up with the following formulae of making natural juice for its industrial area customers
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A fruit/juice kiosk along Lusaka road, VegFresh kiosk has come up with the following formulae of making natural juice for its industrial area customers
- 5 litres lemonade: 2 dozen lemon, 2 kg of sugar, 2 ounces of citric acid and water
- 5 litres grapefruit: 11/2 kg grape fruit, 11/2 kg of sugar, 1 ounces of citric acid and water
- 5 litres orangeade: 11/2 dozen of oranges, 11/2 kg of sugar, 1 ounces of citric acid and water
The selling prices of the fruit juices per every 5 litre are:
Lemonade: Sh. 37.50
Grapefruit: Sh. 40.00
Orangeade: Sh. 42.50
During the cold weather season (May 2002) VegFresh kiosk had in stock 2,500 dozen lemons,2,000 kg grape fruit, 750 dozen oranges, 5,000 kg of sugar and 3,000 ounces of citric acid
Required:
i) Formulate the linear programming problem
ii) Formulate the dual of this primal
Date posted:
February 20, 2019
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Answers (1)
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Define a dual problem in relation to the primal problem
(Solved)
Define a dual problem in relation to the primal problem
Date posted:
February 20, 2019
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Answers (1)
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Given the following data of production of vehicles by a local car assembly KMA Ltd. Determine the deseasonalised data and using the forecasting relationship forecast...
(Solved)
Given the following data of production of vehicles by a local car assembly KMA Ltd. Determine the deseasonalised data and using the forecasting relationship forecast the production in May 2003.
Date posted:
February 20, 2019
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Answers (1)
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What are the steps in time-series decomposition?
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What are the steps in time-series decomposition?
Date posted:
February 20, 2019
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Answers (1)
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Forecasting is the attempt to predict the future by using qualitative or quantitative means. Discuss the qualitative and QUANTITATIVE ANALYSIS available for managers in predicting...
(Solved)
Forecasting is the attempt to predict the future by using qualitative or quantitative means. Discuss the qualitative and QUANTITATIVE ANALYSIS available for managers in predicting the future.
Date posted:
February 20, 2019
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Answers (1)
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i)Explain the meaning of a random variable
ii) Zebro Match Manufacturers finds that 5% of the matches in a box are defective. Determine the probability that...
(Solved)
i)Explain the meaning of a random variable
ii) Zebro Match Manufacturers finds that 5% of the matches in a box are defective. Determine the probability that out of a box containing 50 match sticks:
a) None will be defective
b) If the guarantee is not more than 4 will be defective, what is the probability that the box wil meet guarantee quality?
Date posted:
February 20, 2019
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Answers (1)
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What is a Venn diagram? How can it be used to determine probability of a given event?
(Solved)
What is a Venn diagram? How can it be used to determine probability of a given event?
Date posted:
February 20, 2019
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Answers (1)
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In a base period, salaries comprise 50% of selling price of product, materials and overheads 40%, and profits 10%. If salary structure rose by 20%...
(Solved)
In a base period, salaries comprise 50% of selling price of product, materials and overheads 40%, and profits 10%. If salary structure rose by 20% and materials and overhead costs rose by 10% from base period. What must have been the percentage increase in selling price if profits remained 10% of selling price?
Date posted:
February 20, 2019
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Answers (1)
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The price index for 2001 with base 1985=100 for the listed goods is
(Solved)
The price index for 2001 with base 1985=100 for the listed goods is
Find the Arithmetic mean and geometric mean of these three indices.
Date posted:
February 20, 2019
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Answers (1)
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Write short notes on the following:
i) Price relatives.
ii) Fixed base method.
iii) Chain base method.
iv) Weighted index number.
v) Quantity index number.
(Solved)
Write short notes on the following:
i) Price relatives.
ii) Fixed base method.
iii) Chain base method.
iv) Weighted index number.
v) Quantity index number.
Date posted:
February 20, 2019
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Answers (1)
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In brand switching between different toothpastes named Closed-up CU, Cols-gate CG and Aquas-fresh AF, the state transition matrix below is obtained for a particular month.
(Solved)
In brand switching between different toothpastes named Closed-up CU, Cols-gate CG and Aquas-fresh AF, the state transition matrix below is obtained for a particular month.
Required:
i) If the market share for the different toothpastes were 0.4, 0.3 and 0.3 for CU, CG and AF for January 2002, what will be the market share in February 2002 and March 2002?
ii) What is the market share equilibrium situation?
Date posted:
February 20, 2019
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Answers (1)