Answer: a) Required minimum sample size= 219
b) Required minimum sample size= 271
Step-by-step explanation:
As per given , we have
Margin of error : E= 5% =0.05
Critical z-value for 90% confidence interval : 
a) Prior estimate of true proportion: p=28%=0.28
Formula to find the sample size :-

Required minimum sample size= 219
b) If no estimate of true proportion is given , then we assume p= 0.5
Formula to find the sample size :-

Required minimum sample size= 271
We draw 10 white tiles.
Then we shade in 9 of them.
We count the remaining tiles to get the answer, which is 1.
What problem I cannot see The question
Points are coplanar if they are located on the same plane. A plane is one of the undefined terms in geometry. It is described as a flat surface in a two-dimensional area. If you look at the given figure, find points that are not included in the shaded plane of points A, B and C. That would be point M or point D.