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Hi john sir, guide me about the following:
Q.1 The following four data pairs have been obtained; (1,5), (2,6), (4,9), (5,11). Without carrying out any calculations, which of the following correlation coefficient best describes the relationship between x and y?
a. -9.8
b. -0.25
c. 0.98
d. 0.25John sir answer is given as option c but my question is why not a?
Question 2. John sir, should seasonal variation equal to zero only in additive model? If so , then why not is the case with multiplicative model?
Question 3. John sir confirm the answer.
It is forecasting model based on total cost = fixed cost + variable cost is graphed, the equation is C= F+Vx and the intercept is $7788. If total costs are $14520 and X is 3,000 then the value of the slope, to two decimal places, is:
My answer is 2.24…..Is that correct? Books does’t provide this option.
Q1 If both sets of values increase (or decrease) together, then the coefficient will be positive. If, on the other hand, one set of values increases as the other decreases then the coefficient will be negative. Here, both sets of values move in the same direction and so the coefficient must be positive – so the answer is C.
(I think you have also mistyped A – whatever happens the coefficient has to be between + 1 and – 1).Q2 In the additive model, so variations are positive and some are negative – the total should be 0.
In the multiplicative model, some of the variations will be more than 100% and some will be less than 100% – the total of them should be 400%.Q3 2.244 is correct. (I don’t know what books you are meaning).
Have you watched the free lectures on here? I ask because all of the points you ask are explained in the lectures.
Thanx alot John sir, Yes i had mistyped the question 1, but got it. No John sir i could’t watch the lectures because of internet connection problem. But got it. Thanx for your valueable help.You are great personality.
The original poster was asking just between (a) and (c) which is why I answered the way that I did.
Certainly the correlation is positive, which means the answer is (c) or (d).
By looking at the sets of figures, it is clear that the correlation is fairly close, which means that the coefficient will be nearer to 1 than to 0.
Therefore the answer must be (c).
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