NDA | Mathematics | Mean, Median and Mode

Using given data points tabulated below, a straight line passing through the origin is fitted using least squares method. The slope of the line is

The sum of square of deviation for 10 observation taken from mean 50 is 250. The coefficient of variation is

The mean and variance of a binomial distribution are 4 and 3, respectively. Then the probability of getting exactly six successes in this distribution is

If  and 17.5 is the mode of the following frequency distribution.

Then,

The median class in the following frequency distribution is