To find the mean, add all the numbers together and divide by the amount of numbers there is
89 + 92 + 97 + 81 + 96 = 455
455/5 = 91
91 is Andrew's mean score, and is your answer
hope this helps
A=P (1+r/n)^nt
A= Total amount invested, P=principal amount, r=Interest rate, n=number of time in a year when the interest is earned (for annual, n=1; for semi-annual, n=2, ...), t = time in years
In the current scenario, case 1, n=2; case 2, n=1 and A1=A2, t1=t2
Therefore,
800(1+0.0698/2)^2t = 1000(1+0.0543/1)t
Dividing by 800 on both sides;
(1+0.0349)^2t = 1.25(1+0.02715)^t
(1.0349)^2t = 1.25(1.02715)^t
Taking ln on both sides of the above equation;
2t*ln (1.0349)= ln 1.25 + t*ln (1.02715)
2t*0.0343 = 0.2231+ t*0.0268
0.0686 t = 0.2231+0.0268 t
(0.0686-0.0268)t = 0.2231
0.0418t=0.2231
t=5.337 years
Therefore, after 5.337 years or 5 years and approximately 4 months, their value of investments will be equal.
This value will be,
A=800(1+0.0698/2)^2*5.337 = $1,153.76
6 inches. explanation: if 2 in= 1 mile then multiple 2 by 3 (# of miles) & you get 6
If you multiply the first equation by 2, you get the second equation. Consequently, these equations are said to be "depenent", so both describe the same line. Any of the infinite number of points on the line is a solution, so ...
... The system has infinitely many solutions.
