Let the length and speed of the train ‘A’ be ‘l’ metre and ‘s’ m/s, respectively. According to question, l = 8s Also, 12s = 8s + 140 Or, 4s = 140 Or, s = 35 Therefore, length of train ‘A’ = 8s = 280 metres Length of train ‘B’ = 280 × (5/2) = 700 metres Required time taken = 700 ÷ 25 = 28 seconds
If first, second, and third moment about origin are 1, 6, and 15 respectively, then Karl Pearson beta coefficient of skewness β is
By the method of moving averages, the seasonal index for four quarters equals to:
The standard error of the given data 15, 5, 12, 10, 20, 4 is
If moment generating function of discrete random variable X is (q + pet )n , then E(X2) equals to
X and Y are independent normal variables with mean 50 and 80 respectively and standard deviation as 4 and 3 respectively. What is the distribution o...
Two data set of size 9 and 6 have standard deviation 3 and 4 respectively and arithmetic means 3 and 3 respectively. The standard deviation of combined...
If xi | fi , i = 1,2,...n is a frequency distribution with standard deviation 15 and mean 30, the coefficient of variation will be equal to:
For a random variable x, the central moments (µi) of all order exist. The square of (2j + 1)th moment (µ22j+1) is
The prices (in ₹) of different yarns (per kg) in two consecutive years are as follows.
