7. Let X1, X2,....X18 be eighteen observations such that (X; -) = 36 and (X,-B) = 90, where a i=1 i=1 and are distinct real numbers. If the standard deviation of these observations is 1, then the value of |-B is........ 8. If Im,n = x-1 (1-x)" dx, for m, n1, and -(1 9. 1 X-1 +x-1 dx=alm, then a equals......... (1+x)' m+n Let the normal at all the points on a given curve pass through a fixed point (a, b). If the curve passes through (3,-3) and (4,-22) and given that a-22b=3, then (a +b +ab) is equal to.............. 1 0 0 10. If the matrix A 02 3 0 0 satisfies the equation A20 = A 19 + BA= -1 numbers a and , then -a is equal to........ 1 0 0 = 040 for some real 0 0 1