00:01
In this question, we want to test the claim by the humane society that less than 70 % of households in a certain country own a pet.
00:10
So this is a claim that the proportion, population proportion of this country, is smaller than 0 .7.
00:16
And we are asked to test at a significance level of alpha equals 0 .01.
00:22
To do so, we have a sample of size 500, and out of 500, 335, say they own a pet.
00:31
Now the first step is to identify the hypotheses.
00:35
The null hypothesis would be that the population proportion is 70%.
00:43
And the alternative is that the population proportion is less than .7.
00:50
So that's the claim.
00:54
You can also have greater than equals to for the null hypothesis.
00:59
So the correct answer there is option d.
01:03
And then to test the claim, our test statistic is based on the standard normal distribution.
01:11
That's for a large sample proportion.
01:14
It's calculated as the sample proportion minus the null hypothesized proportion, divided by the square root of the null proportion times 1 minus the null proportion over the sample size...