Instructions

For the following questions answer them individually

Question 144

If the standard deviation of 5, 7, 9, .... 151 is $$\sigma$$, then the standard deviation of 32, 44, 56. .... 908 is

Question 146

If the sum of the squares of deviations of ranks of two students in five subjects is 16, then the coefficient of rank correlation is

Question 147

A fair coin is tossed repeatedly. If tail appears on first four tosses, then the probability of head appearing onfifth toss is

Question 148

If a number is selected at random out of the first 120 natural numbers, then the probability that it is divisible by 5 or 8 is

Question 149

If a coin is tossed five times the probability that at least one head appears on the top is

Question 150

If A and B are two events in a random experiment with $$P(A) = \frac{3}{8}, P(B) = \frac{5}{8}$$ and $$P(A \cap B) = \frac{1}{4}$$, then $$P(A \cup B) =$$