Answer:
5.5217
4.9475
Step-by-step explanation:
Given that :
Mean (m) = 5.3
Standard deviation (s) = 0.3
Score
Minimum redbloodcell in top 23% count
Z = (x - m) / s
Z at 0.23 = 0.739
P(z> x) = 0.23 ; Z = 0.739
0.739 = (x - 5.3) / 0.3
0.739 * 0.3 = x - 5.3
0.2217 = x - 5.3
x = 0.2217 + 5.3
x = 5.5217
(b) What is the maximum red blood cell count that can be in the bottom 12% of counts?
Z = (x - m) / s
P(z< x) = 0.12 ; Z = - 1.175 ( Z probability
-1.175 = (x - 5.3) / 0.3
-1.175 * 0.3 = x - 5.3
- 0.3525 = x - 5.3
x = - 0.352 + 5.3
x = 4.9475