Answer:
-9
Step-by-step explanation:
You take them both and multiply then divide then subtract
Answer: 61,750 miles
Step-by-step explanation:
Given : The p-value of the tires to outlast the warranty = 0.96
The probability that corresponds to 0.96 from a Normal distribution table is 1.75.
Mean : ![\mu=60,000\text{ miles}](https://tex.z-dn.net/?f=%5Cmu%3D60%2C000%5Ctext%7B%20miles%7D)
Standard deviation : ![\sigma=1000\text{ miles}](https://tex.z-dn.net/?f=%5Csigma%3D1000%5Ctext%7B%20miles%7D)
The formula for z-score is given by : -
![z=\dfrac{x-\mu}{\sigma}\\\\\Rightarrow\ 1.75=\dfrac{x-60000}{1000}\\\\\Rightarrow\ x-60000=1750\\\\\Rightarrow\ x=61750](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D%5C%5C%5C%5C%5CRightarrow%5C%201.75%3D%5Cdfrac%7Bx-60000%7D%7B1000%7D%5C%5C%5C%5C%5CRightarrow%5C%20x-60000%3D1750%5C%5C%5C%5C%5CRightarrow%5C%20x%3D61750)
Hence, the tread life of tire should be 61,750 miles if they want 96% of the tires to outlast the warranty.
Because like terms you add or subtract together to make it easier to do the problem. just like you do with whole numbers. you add an subtract to make the answer simpler.