In this lab we will be finding a confidence interval for a single population mean, doing a test of significance for a single population mean, and comparing two population means by comparing sample means drawn independently from different populations.

1. For the first part of this lab you will estimate the mean age of  pennies.  A number pennies were collected early in 2001.  These data can be found here.  We will assume that this is a simple random sample for all the pennies in circulation at that time.
   
1. Graph the penny data in a histogram and describe its shape.  (Graph > Histogram > Simple)
2. Find the sample mean and standard deviation.  (Stat > Basic Statistics > Display Descriptive Statistics)
   
3. Find a 95% confidence interval for the population mean for the data set.  (Stat > Basic Statistics > 1-Sample t)
4. Given the shape of the distribution and the size of the sample, explain if it is appropriate to use the t-procedures on the data.  Explain this so I know the you understand how size and shape affect the use of the t-procedures.
5. What is the standard error of the mean for this data set?

2. For the next part of the lab, we will look at weights of coffee.  Ten samples of 0.5 pound bags of hazelnut coffee from a local coffee house were weighed.  The results, in pounds, are as follows.

1. Find the sample mean and standard deviation for the coffee data.
2. Using the coffee data, determine if the population mean of all hazelnut coffee has a mean weight less than the label weight of 0.5 pounds.  Report the hypotheses, t-statistic, P-value, and conclusion (write the conclusion out in words using no symbols.)  (Stat > Basic Statistics > 1-Sample t.  Put in 0.5 for the Test Mean, click on options and choose the appropriate alternative hypothesis.)

3. Are females hotter than males?  Believe it or not, we can answer this question with statistics.  A data set containing the body temperatures and heart rate for 65 men and 65 women can be found here.  We will use this data set to answer the questions:  "Do women have a higher mean body temperature than men?" and "Do women have a higher heart rate than men?"

1. Find the mean body temperatures and mean heart rates for both men and women. (Stat > Basic Statistics > Display Descriptive Statistics.  Make sure you click on By variable: and put Gender in the box.)  Which group has the higher sample mean temperature? Which group has the higher sample mean heart rate?
2. Make side-by-side boxplots for the body temperatures for both genders.   (Graph > Boxplot > One Y with Groups).  Put  Temp in for the Graph variables: and Gender in for the Categorical variables:.)   Make sure the pair of boxplots is labeled appropriately.  (To relabel the categorical variables double click on the x-axis > click on labels > click on specified > put "Male Female" in the box.)
   
3. Make side-by-side boxplots for the heart rates for both genders.
4. Complete a two-sample t test to see if the mean body temperature for females, in general, is higher than the mean body temperature for males. (Stat > Basic Statistics > 2-Sample t.  Click on sample in one column, in Samples: put Temp and for Subscripts: put Gender.  Under Options you are going to want the appropriate alternative hypothesis, you will want the mean of the males (1) less than the mean of the females (2).)  Report the hypotheses, t-statistic, P-value, and conclusion.
5. Complete a two-sample t test to see if the mean heart rate for females, in general, is higher than the mean heart rate for males. (Stat > Basic Statistics > 2-Sample t.) Make sure you choose the appropriate alternative hypothesis.  Report the hypotheses, t-statistic, P-value, and conclusion.