Answer: 
Step-by-step explanation:
Given
The temperature on Tuesday is 
Temperature drops to
on Wednesday
Net drop in temperature 
The temperature drops twice from Wednesday to Thursday

Temperature on Thursday

Answer:
b
Step-by-step explanation:
Fill the 200mL beaker all of the way. Using the water in that beaker, fill and pour out the 30mL twice and the 40mL three times. You should be left with 20mL in the 200mL beaker.
Given:
n = 40, sample size
Confidence level = 99% => z* = 2.58

, sample proportion.
By definition, the margin of error is

Answer:
According to Sarah's poll, she can conclude with 99% confidence level that 20% of the high school population is happy with the quality of the cafeteria food, with a margin of error of +/- 16.3%.