Answer:
Between 21 years and 75 years
Step-by-step explanation:
Given that a real estate company is interested in the ages of home buyers. They examined the ages of thousands of home buyers and found that the mean age was 48 years old, with a standard deviation of 9 years.
X the ages of home buyers is N(48, 9)
a) 
Hence using Cheby chev inequality

b) 

c) Using normal distribution we have

d) z value is 2.97
Hence x lies between

Between 21 years and 75 years
Answer:
Step-by-step explanation:
Hello!
10*17 = > 170 cm²
(3,14 * 8)/4 =>6,28cm²
170 + 6,28 => 176,28cm²
Answer:
25% or 30L
Step-by-step explanation:
100% is 120L, we know 75% is acid, we need the other 25% to make the 100%. 25% of 120 is 30, so 30 liters is pure acid
It would be a reflection across the x acess