Answer:
after 4 seconds
Step-by-step explanation:
Given
h = 20 - 5(t - 2)²
When rocket is on ground then h = 0
Equate to zero and solve for t
20 - 5(t - 2)² = 0 ( subtract 20 from both sides )
- 5(t - 2)² = - 20 ( divide both sides by - 5 )
(t - 2)² = 4 ( take the square root of both sides )
t - 2 = ± 
= ± 2 ( add 2 to both sides )
t = 2 ± 2
Thus
t = 2 - 2 = 0 ← when rocket is launched
t = 2 + 2 = 4 ← when rocket hits the ground
The rocket reaches the ground after 4 seconds
Use the compounding interest formula here:
There will be about 4,489 dollars on the account after 18 years.
Answer:
a) t = 2.8982
b) 1.826
Step-by-step explanation:
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 18 - 1 = 17
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of ![1 - \frac{1 - 0.99}{2} = 0.995([tex]t_{.995}](https://tex.z-dn.net/?f=1%20-%20%5Cfrac%7B1%20-%200.99%7D%7B2%7D%20%3D%200.995%28%5Btex%5Dt_%7B.995%7D)
). So we have T = 2.8982. This is the answer for a.
The margin of error is:
M = T*s = 2.8982*0.63 = 1.826
In which s is the standard deviation of the sample.
Answer:
D. Grant did not regroup the 4 tens when he subtracted 7.
Step-by-step explanation:
In the process of subtraction, regrouping is important so that each digit in the given numbers are placed appropriately before the required arithmetic operation is performed.
The correct step to Grant's solution are:
360 - 100 = 260
260 - 20 = 240
240 - 7 = 233
Grant's final answer ought to have been 233.
Going through his solution, he made a mistake while subtracting 7 from 240. He failed to regroup the 4 tens when he subtracted 7 from 240. Thus the essence of his wrong answer.
Answer:
Kevin eats 1 pie for every 33 seconds that pass
Step-by-step explanation:
A unit rate is a rate with 1 in the denominator. If you have a rate, such as price per some number of items, and the quantity in the denominator is not 1, you can calculate unit rate or price per unit by completing the division operation: numerator divided by denominator.
If we were wondering how many seconds Kevin takes to eat a pie then the equation would look like:
132 seconds / 4 pies = 33 seconds per pie
33 seconds / 1 pie
However, if we were looking for how many pies Kevin eats in a second, then the equation would look like:
4 pies / 132 = .0303 or 3.03% of a pie per second
.0303 pies / 1 second
