Find attached a graph that I constructed.
To do that graph I used Excel.
First I did a table with this set of points:
<span><span><span>height presuure
</span>
<span>
miles psi
</span>
<span>
0
14,7
</span>
<span>
<---- initial data
3.6 7.35
</span>
<span>
<--- increase hegiht 3.6 miles => half pressure
7.2
3.675
</span>
<span>
<---- second increase of 3.6 miles in height
10. 8
1.8375
</span>
<span>
<---- third increase of 3.6 miles in height
14.4
0.91875
</span>
<span>
18 0.459375
</span>
</span></span>
Let x represent amount invested in the higher-yielding account.
We have been given that a man puts twice as much in the lower-yielding account because it is less risky. So amount invested in the lower-yielding account would be
.
We are also told that his annual interest is $6600 dollars. We know that annual interest for one year will be principal amount times interest rate.
, where,
I = Amount of interest,
P = Principal amount,
r = Annual interest rate in decimal form,
t = Time in years.
We are told that interest rates are 6% and 10%.


Amount of interest earned from lower-yielding account:
.
Amount of interest earned from higher-yielding account:
.

Let us solve for x.



Therefore, the man invested $30,000 at 10%.
Amount invested in the lower-yielding account would be
.
Therefore, the man invested $60,000 at 6%.
Answer:
I'm pretty sure it's the first and last one