A variable is normally distributed with mean 18 and standard deviation 3.
(a) Determine the quartiles of the variable
b)obtain and interpret the 85th percentile
C) Find the value that 65% of all possible
values of the variable exceed
d) Find the two values that divide the area
under the corresponding normal curve into a
middle area of 0.95 and two outside areas of
0.025. Interpret the answer

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.