## Find Margin of Error for t-distribution Confidence Interval

## 8.4.14 Difference Between Proportions StatCrunch

A Two-sample problem for testing to see if the two proportions are different:

## Pick-a-Problem: What difference does it make? 8.1.27

Question: The problem I struggled with this week is 8.1.27. It seemed like all the rest of the problems in the first chapter, but I got it wrong because I used “0” instead of the µ1-µ2 value. Not sure when I am supposed to use that value or how it is determined. I used the […]

## Pick-a-Problem: Not given values for µ in 8.1.11

Question: I have hit the wall on a simple problem. I seem to be hitting these more often now. At any rate. 8.1.11, the difference between two means hypothesis test standardized test statistic requires µ1 – µ2. So, how does one calculate this when we are never given a value for μ? I used 0 for […]

## Confidence Interval for a Mean using StatCrunch

If you are given summary data and asked to find a confidence interval, it is relatively easy using StatCrunch. Here is a typical problem: In this problem, you are told to use the t-distribution, but that may not always be the case. If you are given the sample standard deviation, s, instead of the population […]

## 7.4.5 Single Sample Hypothesis Test for a Proportion

Here is the screenshot of the basic StatCrunch solution. [My Excel calculator for running this test is found here.] As always for proportion problems, we have to check first to be sure np and nq or n*(1-p) are both > 5. If they are, we can use the normal approximation to the binomial (a proportion […]