Business Statistics

If r₁₂ = 0.9, r₁₃ = 0.75, r₂₃ = 0.7, find r_1.23

If r_xy = 0.38, r_yz = 0.91 and r_xz = 0.62. Find the partial correlation between x and y with z as fixed variable.

21 students took a exam. The sample variance is foundto be 80. The examiner claimsthat based on his past experience the true variance has been atleast 100. Does the sample result shows that the population variance significantly less than 100?
[Hint $${x^2} = \frac{{\left( {r - 1} \right)s}}{{{\sigma ^2}}} = \frac{{\left( {21 - 1} \right) \times 80}}{{100}} = 16$$
The value of x² for 20 df 5% level of significance is 31.4. x² value is less than table value.]

A random sample of 15 pairs of values of X and Y from a normal population gives a correlation coefficient of +0.6. Is the correlation in the population significant?

Assumptions of Karl Pearson's co-efficient of correlation includes

Both the regression coefficients cannot be

Z-test is a

Given

Sale price of product X	Sale price of product Y
1	33
4	27
7	23
9	17
15	15
17	14
25	11
30	6

The above values expressed to the

If A and B are two mutually exclusive events, then probability that either of the two events will appear is the sum of their

Suppose that in key punching of 80 column IBM cards, the mean number of mistakes per card is 0.3. What per cent of cards will have no mistake?