00:01
The incomes of families in a particular suburb can be represented by a continuous random variable.
00:06
It is known that 50 % of all families in a suburb have incomes below $55 ,000 and 30 % of all families in a suburb have incomes above $67 ,000.
00:17
So for a, since for a randomly chosen family, what's the probability that the income is between $55 ,000 and $67 ,000? so if we split this apart, we have the probability of x being less than $67 ,000 minus the probability of x being less than $55 ,000.
00:50
Well, let's rewrite this first one to be 1 minus the probability of x being greater than $67 ,000.
01:00
And we know the probability of being less than $55 ,000 is 0 .5.
01:07
So simplifying this, this would be 1 minus being above $67 ,000 is 0 .3...