00:01
The player in exercise 55 has new sneakers, which he thinks improved his game.
00:05
Over the past 60 shots, he's made 32, much better than his 50 % he usually shoots.
00:14
Do you think his chances of making a shot really increased? in other words, is making at least 32 of 60 shots really unusual for him? let's put it this way.
00:27
Well, n is going to be 60 now.
00:35
P is still 0 .55 that we're testing.
00:41
And so if we, 60 times .55 is more than 10, and 60 times .45 as complement is also bigger than 10.
01:00
So that means a normal approximation, those requirements are met.
01:06
And so we can then approximate the binomial distribution by the normal distribution.
01:12
And the z score is the value decreased by the mean and divided by the standard deviation npq where q is 1 minus p and so in this case it would be making 32 of his 60 let's see what we got here 32 minus 60 times 0 .55 over the square root of 60 times 0 .55 times 0 .45 is negative 0259...