Collection of data

SEQ CHAPTER \h \r 1PROJECT FOR Statistics

(Project counts for 100 points)

Project Due Dates

1. Determination of type of data to be collected, and a statement as to what the mean value or proportion is expected to be. This mean value or proportion will be considered to be a true population mean value, μ, or proportion, P, and it will be your null hypothesis. Due Thursday, April 5th. Complete project with data analysis. Due Tuesday, April 24th.

2 Determine the sample size required for a given margin of error. Even though the sample size for this project will be at least 30 data points (for mean values), calculate the required sample size. Calculate the sample size for a 90% and a 95% confidence interval. To do this, E and σ will have to be estimated. Think about the maximum error of estimate (E) that is desired and the amount of variability you expect to see in the data. For proportional data, only E has to be estimated. Three percent is a typical value for E.

Elements of the Project

1. Collect the desired data (at least 30 samples). Describe when, where, and how the data was obtained. Proportional data typically has a couple hundred values.

2. For mean values, calculate the mean, median, and mode for the sample set. Also determine the variance and standard deviation for the sample set. For proportional data, state the proportion and sample standard deviation.

3. For mean values, plot a frequency distribution histogram for the data. This will require choosing the number of classes desired and determining the class width. Show where the mean, median, and mode occur in the diagram. State whether the distribution is approximately normal or if it appears negatively or positively skewed. For proportional data, present a pie chart.

4. Using the sample standard deviation, use the formula for Confidence Limits and calculate a 90% and 95% confidence interval of the mean.

5. Using the z or t test, make a decision to reject or not reject the null hypothesis. Do this for both a 90% and a 95% level of significance. This could be a one tail or a two tailed test.

6. Write a report corresponding to the above numbers. Present the report in a folder, and be prepared to discuss in class. Was the null hypothesis accepted or rejected?