Answer:
(a) Y = 129.3x (b) It is an estimate as it may not be a true reflection of a student's height
Step-by-step explanation:
(a) Estimate of the mean height is the sum of the heights of all the students divided by the total number of students.
The question however needs more information for its estimation as 129.3cm is representative and may be the mean height but it was not stated.
However, assuming it is the mean height,
Let the total number of students be x
while Y is the sum of all individual student heights
Mathematically, mean = Y/x
Therefore 129.3 = Y/ x
implying that Y = 129.3x
(b) It is an estimate because computation of the mean gives an average which may not be an exact value. For example, the mean here is 129.3 whereas there will be many heights greater than that and some lesser than that and obviously, there may be no student with height of 129.3 hence it is an estimate.
Answer:
$215,892.50
Step-by-step explanation:
This is a problem of compound interest.
In compound interest Amount A for principal p charged at interest r% per annum is given by
A = p(1+r/100)^n
where n is the time period in years.
_____________________________
given
p = $100,000
r = 8%
t = 10 years
A= 100,000( 1+ 8/100)^10
A= 100,000( 1.08)^10
A = $215,892.50
So , you need to pay $215,892.50 in total to debt cleared of debt.
NASA launches a rocket at t = 0 seconds. Its height, in meters above sea-level, as a function of time is given by

The sea level is represented by h = 0, therefore, to find the corresponding time when h splashes into the ocean we have to solve for t the following equation:

Using the quadratic formula, the solution for our problem is

The rocket splashes after 26.845 seconds.
The maximum of this function happens at the root of the derivative. Differentiating our function, we have

The root is

Then, the maximum height is

1029.99 meters above sea level.