Identify the formula used to calculate z-score. a. (Mean - Value)/Standard Deviation b. (Mean - Value)/(Mean + Value) c. (Value - Mean)/Standard Deviation d. (Value - Mean)/Median

c

Step-by-step explanation:

in the attachment

answer: 8.5x + 20 < 54

Less than 4 tubes.

Step-by-step explanation:

Assume that x represents the number of tubes of paint Catherine can buy.

Catherine has $54. She plans to spend more than $20 of the money for a painting canvas. The rest will go toward paints. This means that the amount she has to spent on paint is < 54 - 20

Each tube of paint costs $8.50. The cost of x tubes of paint would be 8.5x

Therefore, the inequality that best represents the scenario is

8.5x < 54 - 20

8.5x + 20 < 54

The number of tubes that she can buy is

8.5x < 34

x < 34/8.5

x < 4

Less than 4 tubes