Answer:
B or just google it
Step-by-step explanation:
Rational numbers:
Fractions
Decimals
Whole numbers
Etc.
Answer:

--- Variance
Step-by-step explanation:
Given

Solving (a): Calculate the mean.
The given data is a grouped data. So, first we calculate the class midpoint (x)
For 51 - 58.

For 59 - 66

For 67 - 74

For 75 - 82

For 83 - 90

So, the table becomes:

The mean is then calculated as:



-- approximated
Solving (b): The sample variance:
This is calculated as:

So, we have:


-- approximated
Step-by-step explanation:
The Answer should be 10 as the diving board is the same distance above the surface which is 10
The possibility of selecting a 4 characters long password consisting of 3 letters and one number if letters cannot be repeated and the password must end with a number is 156000
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more number and variables.
The possibility of selecting the password = 26 * 25 * 24 * 10 = 156000
The possibility of selecting a 4 characters long password consisting of 3 letters and one number if letters cannot be repeated and the password must end with a number is 156000
Find out more on equation at: brainly.com/question/2972832
#SPJ4