1. She can buy 5 cupcakes and spend 30 dollars.
2. So she can by 5 more cookies with the rest of her money.
Answer:
The time(s) the ball is higher than the building: Interval (0,4)
Step-by-step explanation:
s(t)=-16t^2+64t+400
Determine the time(s) the ball is higher than the building:
s(t)>400
-16t^2+64t+400>400
Subtracting 400 both sides on the inequality:
-16t^2+64t+400-400>400-400
-16t^2+64t>0
Multiplying the inequality by -1:
(-1)(-16t^2+64t>0)
16t^2-64t<0
Fatorizing: Comon factor 16t:
16t(16t^2/16t-64t/16t)<0
16t(t-4)<0
t is greater than zero:
t>0→t-4<0→t-4+4<0+4→t<4
Then t>0 ant t<4:
Solution = (0, Infinite) ∩ (-Infinite, 4)
Solution = (0,4)
The answer would be 12 feet square.
That’s because taking out the square is taking out an area of 4 feet square. If you substitute the 4 feet square back in, that would fill in the empty spot marked with the 2 feet by 2 feet dimensions. Then, you could treat it like a rectangle of 4 by 3. If you multiply them you’ll get 12 feet square which is your answer. Hope this helps
Using the normal distribution, it is found that the replacement time that separates the top 18% from the bottom 82% is of 11.23 years.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean 
and standard deviation 
is given by:
- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
In this problem, the mean and the standard deviation are, respectively, given by 
.
The desired value is the 82nd percentile, which is X when Z = 0.915, hence:
X - 9.4 = 0.915(2)
X = 11.23
The replacement time that separates the top 18% from the bottom 82% is of 11.23 years.
More can be learned about the normal distribution at brainly.com/question/24663213
