The answer is . (one [point] 4)
((Yes, its correct, checked and took an exam on it))
Answer:
£390
Step-by-step explanation:
The ratio of money in bank:
Terry : Faye
3 : 7
Terry put £220 in his account
Faye withdrew £300 from her account
Unknown:
Initial amount Terry had = ?
Solution:
Let the real amount terry has = 3x
Faye will have = 7x
Now;
3x + 220 = 7x -300
Solving this equation:
3x + 220 = 7x -300
3x - 7x = -300 - 220
-4x = - 520
4x = 520
x = 130
Originally, Terry has 3x = 3 x 130 = £390
a)
because it is equal to the area of the shaded region between X=4 and X=6, and the probability that X falls within some interval is given by the area under the PDF.
b)
because the shaded region is a rectangle of height 1/5 (by virtue of X following a uniform distribution over the interval [2, 7], which has length 5).
In can be less mental effort if the equation is multiplied by -1 first.
.. x^2 -10x +8 = 0
.. x^2 -10x +25 +8 -25 = 0
.. (x -5)^2 = 17
.. x -5 = ±√17
.. x = 5 ±√17
The values of x that satisfy the given equation are
.. x = 5 -√17 ≈ 0.877
.. x = 5 +√17 ≈ 9.123