two statistics 1450 lab
Qwert01
lab_9b_-_two_sample_means.docxSTAT 1450 – The Practice of Statistics
Hypothesis Testing of Two Means
Lab Assignment _____ Name:
OBJECTIVES:
· To use Excel to calculate p-values when comparing two sample means
· To identify independent and dependent (paired and matched) samples
· To recognize that hypothesis tests for paired and matched samples are treated the same
· To use the p-value method to make conclusions
EXCEL PROCEDURES:
Open the Excel Spreadsheet in Blackboard with data for this lab.
Experiment 1:
Data is collected from a random sample of 16 third grade children reading first without and then with a dog, to see if reading to a dog improves their average reading speed (ie. reading with dog had more wpm). It can be assumed that the reading speeds of the third graders are normally distributed. See Excel spread sheet for data and test the claim at a 0.04 level of significance. Let µ1=without dog
a. Are these samples independent or dependent? Circle one.
If dependent are they matched or paired? Circle one.
b. Ho:
Excel Procedure:
1. In cell C5 type “p-value”.
2. Select cell C6.
3. Select Formulas (tab at top of Excel window)->More Functions->Statistical->T.Test.
4. In the Array1 field select the data for “WPM” and in the Array 2 field select the data for “WPM with dog”.
5. Enter the appropriate number of tails in the Tails field based on your stated Ha.
6. In the Type field enter 1 to indicate dependent samples (Matched or Paired), or enter 3 if independent samples (type 2 is for independent samples with the same standard deviation which is not on this lab).
c. P-value: __________________
d. Conclusion (explain why and interpret in context):
Experiment 2:
Shoe sizes are collected from a random sample of 8 fathers and their adult sons to determine if the mean shoe size for fathers is significantly smaller than the average shoe size of the sons. It can be assumed that the shoes sizes of both the fathers and the sons are normally distributed. See Excel spread sheet for the sample data and test the claim at a 3% level of significance.
a. Are these samples independent or dependent? Circle one.
If dependent are they matched or paired? Circle one.
b. Ho:
Ha:
Excel Procedure:
1. In cell G5 type “p-value”.
2. Select cell G6.
3. Select Formulas (tab at top of Excel window)->More Functions->Statistical->T.Test.
4. In the Array1 field select the data for Fathers and in the Array 2 field select the data for Sons.
5. Enter the appropriate number of tails in the Tails field based on your stated Ha.
6. In the Type field enter 1 to indicate dependent samples (Matched or Paired), or enter 3 if independent samples (type 2 is for independent samples with the same standard deviation which is not on this lab).
c. P-value: __________________
d. Conclusion (explain why and interpret in context):
Experiment 3:
Fifteen female CSCC students and 10 male CSCC students are randomly selected to determine if the mean time studying for females is significantly different than the mean study time for males. It can be assumed that all study times are normally distributed. See Excel spread sheet for the sample data and test the claim at a 0.06 level of significance.
a. Are these samples independent or dependent? Circle one.
If dependent are they matched or paired? Circle one.
b. Ho:
Ha:
Excel Procedure:
1. In cell K5 type “p-value”.
2. Select cell K6.
3. Select Formulas (tab at top of Excel window)->More Functions->Statistical->T.Test.
4. In the Array1 field select the data for the females and in the Array 2 field select the males.
5. Enter the appropriate number of tails in the Tails field based on your stated Ha.
6. In the Type field enter 1 to indicate dependent samples (Matched or Paired), or enter 3 if independent samples (type 2 is for independent samples with the same standard deviation which is not on this lab).
c. P-value: __________________
d. Conclusion (explain why and interpret in context):
Copy and paste the table of results from your three hypothesis tests to the end of this lab.
Two Sample Means Page 1
