MATH 10041 Chapter Notes - Chapter 7: Normal Distribution, Confidence Interval, Sampling Distribution

• School: Kent State University
• Department: Mathematics
• Course: MATH 10041
• Professor: Beverly M Reed

Document Summary

Statistics: a number that is based on data and used to estimate a population parameter: even if the proportions are equal for two populations, the sample proportions drawn from these populations are usually different. Z-scores: you"ve already seen subtraction used to compare numbers. The numerator of the z-score (the observed value minus the sample mean) is used to tell us the distance between a number and the mean of the sample. Independent samples: if the sample are not independent, then the standard error in the confidence interval will be the wrong value, and you"ll have the wrong margin of error. Choosing populations: when comparing proportions from different years, researchers usually choose the most recent year as their population 1. this makes it possible to interpret the difference in proportions as a change across time. Controlled experiments: an important feature of well-designed controlled experiment is that subjects are assigned to treatment and control groups at random.