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 : 
Standard deviation : 
The formula for z-score is given by : -

Hence, the tread life of tire should be 61,750 miles if they want 96% of the tires to outlast the warranty.
When You Evaluate the expression you the Answer D) 54
Answer:
1 hour
Step-by-step explanation:
I find these easiest to work by considering the initial difference in distance and the speed at with that gap is closing.
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The gap is 15 miles, the distance the first ship is from harbor when the second ship starts.
The rate of closure is the difference in the speeds of the two ships:
60 mph -45 mph = 15 mph
Then the closure time is ...
time = distance/speed
time = (15 mi)/(15 mi/h) = 1 h
It will take the second ship 1 hour to catch up to the first ship.