Answer:
a) 0.8333
b) 0.75
c) 0.8181 or 0.9090
Step-by-step explanation:
a)
The probability the visitor selects an authentic painting is
10/12 = 0.8333
b)
Since the opinion of the expert does not depend on your choice, the events are <em>independent</em>, so the probability that the expert says is authentic and it really is, is
0.8333*0.9 = 0.75
c)
If the expert decides the painting is a copy and it is not, then there are 11 paintings of which 9 are authentic, so the probability the visitor selects a new original painting is
9/11= 0.8181
If the expert decides the painting is a copy and it is, then there are 11 paintings of which 10 are authentic, so the probability the visitor selects a new original painting is
10/11= 0.9090
Answer: $28.30✔️
Step-by-step explanation:
Let C = cost before tax
Cell phone costs = C + C·6% = $30
C(1 + 0.06) = $30
C = $30/1.06 = $28.30
Answer: $28.30✔️
<h3> Verify </h3>
Cell phone after tax = $28.30 + $28.30·6/100 = $28.30 + $1.70 = $30✔️
<h2><em>Spymore </em></h2>
Answer:
Equation is: y = 0.5x² + 0.5x - 3
Explanation:
general form of the parabola is:
y = ax² + bx + c
Now, we will need to solve for a, b and c.
To do this, we will simply get points from the graph, substitute in the general equation and solve for the missing coefficients.
First point that we will use is (0,-3).
y = y = ax² + bx + c
-3 = a(0)² + b(0) + c
c = -3
The equation now becomes:
y = ax² + bx - 3
The second point that we will use is (2,0):
y = ax² + bx - 3
0 = a(2)² + b(2) - 3
0 = 4a + 2b -3
4a + 2b = 3
This means that:
2b = 3 - 4a
b = 1.5 - 2a ...........> I
The third point that we will use is (-3,0):
y = ax² + bx - 3
0 = a(-3)² + b(-3) - 3
0 = 9a - 3b - 3
9a - 3b = 3 ...........> II
Substitute with I in II and solve for a as follows:
9a - 3b = 3
9a - 3(1.5 - 2a) = 3
9a - 4.5 + 6a = 3
15a = 7.5
a = 7.5 / 15
a = 0.5
Substitute with the value of a in equation I to get b as follows:
b = 1.5 - 2a
b = 1.5 - 2(0.5)
b = 0.5
Substitute with a and b in the equation as follows:
y = 0.5x² + 0.5x - 3
Hope this helps :)
There are 2 answers: Choice 1, Choice 4
=======================================
Why is this? Because we use the rule
P(A & B) = P(A) * P(B)
which only works if events A and B are independent
----
For the first answer choice,
P(A) * P(B) = 0.6*0.4 = 0.24 = P(A & B)
so that matches.
The same applies to the fourth answer choice as well
P(A) * P(B) = 0.3*0.2= 0.06 = P(A & B)
----
The other answer choices don't match up.
The second answer choice has
P(A) * P(B) = 0.3*0.4 = 0.12 but that doesn't match with the 0.70 given
Similarly for the third answer choice,
P(A) * P(B) = 0.5*0.1 = 0.05 which doesn't match with the 0.60
