1. WARM – UP
Plant scientists have developed a new variety of corn rich in amino acid lysine used for bulking up chickens. Twenty-five Chickens were randomly placed in one of two groups (Exclusively eating the New corn & Control group) and after one month their weight gains were recorded (in grams).
Control Experimental Corn
430
Is there good evidence that chicks fed high-lysine corn gain more weight?

2. Control: 367.75 47.165 12 H0: μ1 = μ2 Ha: μ1 < μ2
Experimental:
μi = The true mean amount of weight gained by chicks eating…
μ1 = Traditional Corn μ2 = Experimental Corn
H0: μ1 = μ2 Ha: μ1 < μ2
TWO Sample
t – Test
SRS – Stated 2. Independent
3. Approximately Normal Distribution – Graph BOTH!
Since the P-Value is less than α = the data IS significant . There is strong evidence to REJECT H0 . Chicks fed the high-lysine corn gained more weight.

3. Two –Sample T Tests vs. Matched Pairs T Tests
Two Sample T – Two INDEPENDENT samples in which no natural pairing exists within the data. Examines the Difference in the Means
Matched Pairs T – Two Dependent samples in which a natural pairing does exist within the data. Examines the Mean of the Paired Differences.

4. Two-Sample vs. Matched Pairs
The following data indicates the average age of registered voters before and after the 2004 election. Choose 6 counties.
County #
Before 04
After 04 1 35 36 2 40 38 3 42 43 4 5 41 37 6 50 49 7 47 8 9 39 10 11 32
1. Design AND Conduct a Two-sample t-Test (both samples n =6) experiment to determine if age significantly decreased.
2. Design AND Conduct a Matched Pairs t-Test (n = 6) experiment to determine if age significantly decreased.

5. Two-Sample vs. Matched Pairs
Randomly Choose 2 samples of 6 counties, 6 B & 6 A.
County #
Before 04
After 04 1 35 36 2 40 38 3 42 43 4 5 41 37 6 50 49 7 47 8 9 39 10 11 32
1. Design AND Conduct a Two-sample t-Test (n =6) experiment to determine if age significantly decreased.
μi= True mean age of voters…
i=1 Before 04, i=2 After 04
H0: μ1 = μ2 Ha: μ1 > μ2
TWO Sample
t – Test
SRS – Stated 2. Independent
3. Approximately Normal Distribution – Graph BOTH!
t = ________ P-Value = _______

6. Two-Sample vs. Matched Pairs
Randomly Choose 6 counties.
2. Design AND Conduct a Matched Pairs t-Test (n = 6) experiment to determine if age significantly decreased.
County #
Before 04
After 04 1 35 36 2 40 38 3 42 43 4 5 41 37 6 50 49 7 47 8 9 39 10 11 32
μd= True mean difference in age of voters. (Before 04, - After 04)
H0: μd = 0 Ha: μd > 0
Matched Pairs
t – Test
SRS – Stated 2. Not Independent
3. Approximately Normal Distribution Graph differences
t = ________ P-Value = _______

7. OBJECTS RECALLED

8. High cholesterol levels in people can be reduced by exercise, diet, and medication. Twenty middle-aged males with cholesterol readings between 220 and 240 milligrams per deciliter (mg/dL) of blood were randomly selected from the population of such male patients at a large local hospital. Ten of the 20 males were randomly assigned to group A, advised on appropriate exercise and diet, and also received a placebo. The other 10 males were assigned to group B, received the same advice on appropriate exercise and diet, but received a drug intended to reduce cholesterol instead of a placebo. After three months, post-treatment cholesterol readings were taken for all 20 males and compared to pretreatment cholesterol readings. The tables below give the reduction in cholesterol level (pretreatment reading minus post-treatment reading) for each male in the study.
Do the data provide convincing evidence, at the α = 0.01 level, that the cholesterol drug is effective in producing a reduction in mean cholesterol level beyond that produced by exercise and diet?