1. Warm Up
Premature babies often have neurological problems and reduced verbal abilities. A 2003 study investigated whether premature babies can recover some of their verbal ability. A random sample of 50 prematurely born children were given a verbal test at age 3 and age 8. The test is scaled so that a score of 100 would be average for normal birth-weight children. n Mean Std Dev Age Age Difference Is this statistically significant data that premature children can recover some of their verbal ability?

2. Practice - Do brand name batteries last longer than generic batteries?
Imagine we conducted an experiment with 6 brand name and 6 generic batteries. We measured the lifetime of each of the batteries, the data is summarized below. n Mean Std Dev Generic min 14.6 min Brand Name min 10.3 min 1) Define Ho and Ha 2) Find t and the P-value for a 2 sample t test

3. Practice
Mr. Clarke conducted a study to see if using calculators on their unit test would help his Algebra 1 students improve their scores. He randomly assigned the 32 students in his class into groups that either used or did not use a calculator. A summary of the scores is below. Is this significant data that using a calculator improved the Algebra 1 students’ scores (assume the distributions are normal)? n Mean Std Dev Calculator No Calculator

4. Practice
A 2010 study in Canada tried to determine if freshmen gain more weight in their first year by living on or off campus. Data on 10 randomly selected students living on-campus and 10 randomly selected students living off-campus is below (weight in kg). Is this statistically significant data that freshmen weight gain is different on-campus vs. off-campus? On Campus Off Campus