Solve the system of equations 15x -2y = 4 20x

The probability that a student has a Visa card (event V) is .73. The probability that a student has a MasterCard (event M) is .1

snow_lady [41]

We assumed in this answer that the question b is, Are the events V and M independent?

Answer:

(a). The probability that a student has either a Visa card or a MasterCard is $\\ P(V \cup M) = 0.88$ . (b). The events V and M are not independent.

Step-by-step explanation:

The key factor to solve these questions is to know that:

$\\ P(V \cup M) = P(V) + P(M) - P(V \cap M)$

We already know from the question the following probabilities:

$\\ P(V) = 0.73$

$\\ P(M) = 0.18$

The probability that a student has both cards is 0.03. It means that the events V AND M occur at the same time. So

$\\ P(V \cap M) = 0.03$

The probability that a student has either a Visa card or a MasterCard

We can interpret this probability as $\\ P(V \cup M)$ or the sum of both events; that is, the probability that one event occurs OR the other.

Thus, having all this information, we can conclude that

$\\ P(V \cup M) = P(V) + P(M) - P(V \cap M)$

$\\ P(V \cup M) = 0.73 + 0.18 - 0.03$

$\\ P(V \cup M) = 0.88$

Then, the probability that a student has either a Visa card or a MasterCard is $\\ P(V \cup M) = 0.88$ .

Are the events V and M independent?

A way to solve this question is by using the concept of conditional probabilities.

In Probability, two events are independent when we conclude that

$\\ P(A|B) = P(A)$ [1]

The general formula for a conditional probability or the probability that event A given (or assuming) the event B is as follows:

$\\ P(A|B) = \frac{P(A \cap B)}{P(B)}$

If we use the previous formula to find conditional probabilities of event M given event V or vice-versa, we can conclude that

$\\ P(M|V) = \frac{P(M \cap V)}{P(V)}$

$\\ P(M|V) = \frac{0.03}{0.73}$

$\\ P(M|V) \approx 0.041$

If M were independent from V (according to [1]), we have

$\\ P(M|V) = P(M) = 0.18$

Which is different from we obtained previously;

That is,

$\\ P(M|V) \approx 0.041$

So, the events V and M are not independent.

We can conclude the same if we calculate the probability

$\\ P(V|M)$ , as follows:

$\\ P(V|M) = \frac{P(V \cap M)}{P(M)}$

$\\ P(V|M) = \frac{0.03}{0.18}$

$\\ P(V|M) = 0.1666.....\approx 0.17$

Which is different from

$\\ P(V|M) = P(V) = 0.73$

In the case that both events were independent.

Notice that

$\\ P(V|M)*P(M) = P(M|V)*P(V) = P(V \cap M) = P(M \cap V)$

$\\ \frac{0.03}{0.18}*0.18 = \frac{0.03}{0.73}*0.73 = 0.03 = 0.03$

$\\ 0.03 = 0.03 = 0.03 = 0.03$

3 0

3 years ago

Fbuhdvbcuhvcukhdvcugj

alexgriva [62]

This isn't even a question, lol

4 0

3 years ago

Read 2 more answers

Can someone plz help with 21?? Thanks!

Romashka-Z-Leto [24]

Answer:

4) -11.3...

Step-by-step explanation:

distribute both sides to get (1/6)x - (4/3) = (4/15)x - (1/5)

move the variables to one side and the constants to the other: ((4/15) - (1/6))x = (-(4/3) + (1/5))

simplify to get (1/10)x = (-17/15) multiply everything by 10 to get x=-34/3 or -11.33333333333333333...

6 0

2 years ago

Read 2 more answers

Rewrite the equationy−2=−2/3 (x+6) in standard form.

Dima020 [189]

Answer:

y=-2/3x-2

Step-by-step explanation:

8 0

2 years ago

Find the lateral area and surface area of a regular hexagonal right prism is the base edges are 10 and the height is 12.

nadezda [96]

Answer:

Step-by-step explanation:

a hexagonal prism is made up of two bases that are hexagons and six faces that are rectangles.

Lateral surface area, LA = Perimeter × height

Perimeter = number of sides × length of each side

Perimeter, P = 6 × 10 = 60

LA = 60 × 12 = 720 units squared

Area of each base, B = 1/2a × perimeter

Where

a = apotherm

We would determine the length of the apotherm of each base of the prism by applying the formula,

a = s/[2tan(180/n)]

Where

s = length of each side = 10

n = 6 sides

a = 10/[2tan(180/6) = 10/[2tan30)

a = 8.66

B = 1/2 × 8.66 × 60 = 259.8

Total surface area = LA + 2B

Total surface area = 720 + 2 × 259.8 = 1239.6 units squared

3 0

3 years ago

Solve the system of equations 15x -2y = 4 20x - 3y = 1