The air pressure of the tire is 34.7 psi
Step-by-step explanation:
The formula of the z-score is z = (x - μ)/σ, where
∵ The air pressure of each tire in a group is normally distributed
with a mean of 39.2 pounds per square inch (psi)
∴ μ = 39.2
∵ A standard deviation of 2.5 psi.
∴ σ = 2.5
∵ This group has a z-score of -1.8
∴ z = -1.8
- Substitute these values in z-score formula
∵ [tex]-1.8=\frac{x-39.2}{2.5}[/tex]
- Multiply both sides by 2.5
∴ -4.5 = x - 39.2
- Add 39.2 to both sides
∴ 34.7 = x
The air pressure of the tire is 34.7 psi
Learn more:
You can learn more about z-score in brainly.com/question/7207785
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