The answer would be 6. 21/3.5=6
A set of data has a normal distribution with a mean of 5.1 and a standard deviation of 0.9. Find the percent of data between 4.2 and 5.1.
Answer: The correct option is B) about 34%
Proof:
We have to find 
To find
, we need to use z score formula:
When x = 4.2, we have:


When x = 5.1, we have:


Therefore, we have to find 
Using the standard normal table, we have:
= 

or 34.13%
= 34% approximately
Therefore, the percent of data between 4.2 and 5.1 is about 34%
Laura is 72 inches tall.
1 feet= 12 inches
12*6=72
Answer:
(a) After t years, the height is
18t² + 3t + 10
(b) The shrubs are847 cm tall when they are sold.
Step-by-step explanation:
Given growth rate
dh/dt = 1.8t + 3
dh = (18t + 3)dt
Integrating this, we have
h = 18t² + 3t + C
When t = 0, h = 10cm
Then
10 = C
So
(a) h = 18t² + 3t + 10
(b) Because they are sold after every 9 years, then at t = 9
h = 18(9)² + 3(9) + 10
= 810 + 27 + 10
= 847 cm