We have the following function:
f(t) = −16t2 + 34t + 546
By definition, the average rate of change is:
Avr = (f (t2) - f (t1)) / (t2 - t1)
We have then:
For t1 = 5:
f (5) = -16*(5)^2 + 34*(5) + 546
f (5) = 316
For t2 = 5:
f (7) = -16*(7)^2 + 34*(7) + 546
f (7) = 0
Substituting values:
Avr = (0 - 316) / (7 - 5)
Avr = -158
Answer:
The average rate of change of f (t) from t = 5 seconds to t = 7 seconds is -158 feet per second.
Answer:
The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. 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 get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the reading speed of a sixth-grader whose reading speed is at the 90th percentile
This is the value of X when Z has a pvalue of 0.9. So it is X when Z = 1.28.




The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Answer:
28 short-sleeved shirts were sold and 23 long-sleeved shirts were sold.
Step-by-step explanation:
We can solve this question by a system of equations.
I am going to say that:
x is the number of short-sleeved shirts sold.
y is the number of long-sleeved shirts sold.
A department store sold 51 shirts one day.
This means that 
All short-sleeved shirts cost $14.00 each and all long-sleeved shirts cost $23.00 each. Total receipts for the day were $921.00.
This means that

How many of each kind of shirt were sold?
We have to solve the system of equations.


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28 short-sleeved shirts were sold and 23 long-sleeved shirts were sold.
Answer:
39
Step-by-step explanation:
you do 180 and subtract both values you already have 102 and 39. you get the answer of 39
Answer:
The answer would be (7,9).
Step-by-step explanation:
If you partition that line by 6 you'd get (3,5), (4,6), (5,7), (6,8), and (7,9) in the middle of the two points. And the ratio of 5:1 would be seen at point (7,9).