00:01
Hey there, welcome to numerade.
00:03
We are given our number of trials here as 7 and a probability here of 0 .7.
00:12
Based on the setup here, we are asked to find the following probabilities in which we will be using a binomial distribution, in which we have combinations times the probability raised to the x, times q raised to the n minus x.
00:32
So with this, starting with part a, we're looking for the probability.
00:36
The x is at least 4.
00:39
So what this basically is equivalent to is the probability of 4 plus the probability of 5.
00:46
And we are going to be adding all the way up to the probability of 7 our sample size.
00:53
Therefore, these probabilities here are going to be plugged in to our equation above and in summed all together.
01:02
Hence, what we get here for our probability will be around 0 .8 -740.
01:16
Part b, probability that x equals 2.
01:20
So we are plugging this directly to our equation above, giving us combinations 7 choose 2, times...