eileen's energy bars has determined that an energy bar measuring 3.25 inches long has a z-score of +1 and an energy bar measuring 3.50 inches long has a z-score of +2.
what is the standard deviation of the length of energy bars produced at eileen's energy bars?
3.5
3.25
0.75
0.25

The standard deviation of the length of energy is 0.25 ⇒ 4th answer

Step-by-step explanation:

* Lets explain how to solve the problem

- An energy bar measuring 3.25 inches long has a z-score of +1

- An energy bar measuring 3.50 inches long has a z-score of +2

- The rule of z-score is ⇒ z = = (x - μ)/σ , where

# x is the score

# μ is the mean

# σ is the standard deviation

∵ z = +1 when x = 3.25 inches

∴ 1 = (3.25 - μ)/σ

- Multiply both sides by σ

∴ σ = 3.25 - μ  

- Add μ to both sides

∴ σ + μ = 3.25 ⇒ (1)

∵ z = +2 when x = 3.50 inches

∴ 2 = (3.50 - μ)/σ

- Multiply both sides by σ

∴ 2σ = 3.50 - μ  

- Add μ to both sides

∴ 2σ + μ = 3.50 ⇒ (2)

* Lets solve equations (1) and (2) to find σ

- Subtract equation (1) from equation (2)

∴ (2σ + μ ) - (σ + μ) = 3.50 - 3.25

∴ σ = 0.25

∵ σ is the standard deviation

∴ The standard deviation of the length of energy is 0.25

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.