Answer: in order to qualify, the time must be at least 15.93 minutes
Step-by-step explanation:
Let x be a random variable representing the average response times of fire departments to fire calls. Since it follows a normal distribution, we will determine the z score by applying the formula,
z = (x - µ)/σ
Where
x = sample mean
µ = population mean
σ = population standard deviation
From the information given,
µ = 12.8 minutes
σ = 3.7 minutes
in order to qualify for the special safety award, the probability value would be to the right of the z score corresponding to 80%
The z score corresponding to 80% on the normal distribution table is 0.845
Therefore,
0.845 = (x - 12.8)/3.7
0.845 × 3.7 = x - 12.8
3.13 = x - 12.8
x = 12.8 + 3.13 = 15.93
He traveled 2080 miles after 4 hours. He covered 3640 miles in 7 hours with a constant speed, so we can calculate the speed: 3640/7=520 miles/hour. After 4 hours, he traveled 520*4=2080 miles.
Answer:
What are the options?
Step-by-step explanation:
Answer:
b. x+y=18
20x+25y=400
Step-by-step explanation:
Answer:
4180 to 5230$
Step-by-step explanation:
1. Lets find the expenses she has to make -> 4*90+660=1020$(4 new tires + other expenses)
2. As her income is not set strictly we can guess the range she can save(More accurate calculations depends on her strict incomes). We have 5200-1020=4180$(if she gets paid 5200$) and 6250-1020= 5230$(if she gets paid 6250$).
3. So the range of savings vary from 4180 to 5230$$.
