Answer:
Because she is concluding that her class is an accurate representation of the overall school. The sample size in this case is too small and should increase her sample size(the amount of people surveyed) in order to get a better result.
Answer: He would pay 45% of the original price.
Step-by-step explanation:
Since we have given that
Let the original price of item be 'x'
Rate mark down by 25%
Amount of marked down would be

Amount after marked down becomes

Additional clearance items by 40% off
Amount of additional off is given by

After additional off, the amount becomes,

Hence, he would pay 45% of the original price.
Integer??? Idk I'm sorry....