Answer:
Step-by-step explanation:
If the radius, r, is given, then the area of the circle is A = πr².
If the diameter, d, is given, then the circle area is A = π(d/2)², or A = πd² / 4.
Answer:
b) 1.34
Step-by-step explanation:
The z score is used to determine the number of standard deviations by which the raw score is above or below the mean. If the z score is positive then the z score is above the mean while for a negative z score implies that it is below the mean. The z score is given by:

For the largest 9%, the score is 100% - 9% = 91% = 0.91
From the normal distribution table, the z score that corresponds to 0.91 is 1.34
The volume of the first figure: 904.78 m^3
the volume of the second figure: 113.1 m^3
Difference: 904.78-113.1= 791.68
Null hypothesis: 
Alternative hypothesis: 
The null is based on a recent study that 81% of the population (in this case senior citizens) takes at least one medication. The alternative hypothesis is basically the flip of the claim made in the null.
If Amelia wanted to know if the percentage was less than 81%, then the alternative would be p < 0.81
If Amelia wanted to know if the percentage was larger than 81%, then the alternative would be p > 0.81
However, she wants to know if the percentage is 81%.
For the first one it’s D.3