Answer:
.................. ........
Reason number 1 (before) is that you could contaminate your samples if you have foreign material on your hands.
Reason number 2 (after) is that you could spread<span>/or ingest dangerous chemicals or substances that you have handled in the lab.</span>
Answer:
(-3.07, 11.07)
Step-by-step explanation:
Given that a sports writer wished to see if a football filled with helium travels farther, on average, than a football filled with air. To test this, the writer used eighteen adult male volunteers. These volunteers were randomly divided into two groups of nine subjects each.
Group Group One Group Two
Mean 300.00 296.00
SD 8.00 6.00
SEM 2.67 2.00
N 9 9
The mean of Group One minus Group Two equals 4.00
standard error of difference = 3.333
df = 16
t = 1.2000
Margin of error = 3.3333* t critical = 3.3333*2.121
95% confidence interval of this difference: From -3.07 to 11.07