00:01
Hey there, welcome to numerate.
00:03
We're asked to construct an 80 % confidence interval for the population proportion.
00:08
We're out of a sample size of 538 customers, 7 to 8 of them experience and interruption in their high -speed service.
00:16
So with this, we have 80%, so this is our confidence interval for proportions.
00:22
So let's plug in our values here.
00:25
We're going to have a proportion.
00:27
So we really found it at 0 .1.
00:30
145 for our p from above so let me confirm that yep 0 .145 and we just round to 0 .15 so let's put that for p so if we have confidence interval equals 0 .15 plus a minus z critical based on 80 % on confidence level is 1 .28 multiplied by the square root square root of the proportion again which is 0 .15.
01:23
1 minus 0 .15 is basically 0 .85 and this is going to be divided by the sample size which we have as 538 customers.
01:44
Alright so let's divide this out and see what we get...