Basic Probability Question, attached a photo! Please help. Thanks!

okay wait before i answer, is this for your points on a graph?

2.56 is the width of the garden

step-by-step explanation:

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!