And so she decides to estimate the true percentage by sampling 300 individual bacterium, or I always forget the singular case, by sampling 300 bacteria. And then in her sample, she found that 94% of them were dead and then the margin of error tells us, because the margin of error says that it's unlikely, or that it's very likely that the true percentage is above 90%, that means that given that you sampled 300 bacteria, it's very unlikely that the true percentage is below 90%. So she could feel reasonably confident that in her Petri dish, more than 90% of the population did indeed die. Now let's answer these questions. What type of statistical study did Alma use? Well, she used a, she's trying to estimate a parameter for a population, in this case, the parameter was the percentage of all of the bacteria that died, she couldn't observe that directly, so instead, she took a random sample of the bacteria in the Petri dish, and she used, she calculated a statistic for them, 94% of them were dead, and that's her estimate for the population parameter, the percentage of the population that died. So this is, when you're using a random sample to generate a statistic which estimates a parameter for a population, that's a sample study.