Answer:
D. The rate of change must be 20 pounds per minute.
Step-by-step explanation:
At time 0, the amount of sand is 200 lb. Time zero is when it starts, so it is also called the initial time. The initial value is 200 lb, so choices A and B are wrong.
Now look at the difference from time 0 minutes to time 1 minute. The amount of sand went from 200 lb to 220 lb. The amount of sand placed in 1 minute is 20 lb, so the rate of change is 20 lb per minute. That makes choice C wrong and choice D correct.
Answer: D. The rate of change must be 20 pounds per minute.
Answer:
1/3
Step-by-step explanation:
Answer:
The standard deviation of the speeds of cars travelling on California freeway is 6.0088 miles per hour.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we This p-value is the probability that the value of the measure is greater than X.
In this problem, we have that:
Suppose that the speeds of cars travelling on California freeways are normally distributed with a mean of 61 miles/hour. This means that
.
The highway patrol's policy is to issue tickets for cars with speeds exceeding 75 miles/hour. The records show that exactly 1% of the speeds exceed this limit. This means that the pvalue of Z when
is 0.99. This is 
So





The standard deviation of the speeds of cars travelling on California freeway is 6.0088 miles per hour.
Answer:
3 hours 5 minutes
Step-by-step explanation:
1 hour + 1 hour = 2hrs
15 minutes + 50 minutes = 65 minutes
65 minutes to 1 hr = 1 hr 5 minutes
2 hours + 1 hr 5 minutes = 3 hours 5 minutes
1.125.........................................................................