Answer:
We need a sample size of least 119
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Sample size needed
At least n, in which n is found when 
We don't know the proportion, so we use
, which is when we would need the largest sample size.






Rounding up
We need a sample size of least 119
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.
Answer:
20%
Step-by-step explanation:
400/2000=0.2
0.2*100=20
Answer:
Triangular Pyramid
Step-by-step explanation:
Answer:
That is wrong
Step-by-step explanation:
1.55 rounds up, 7.95 round up. Remember, they are supposed to round down.
Also, if you could label this brainliest that would be a great help!
Thanks xx
-Dante