Disks of polycarbonate plastic from a supplier are analyzed for scratch and shock resistance. The results from 100 disks are summarized as follows:

shock resistance
scratch resistance high low
high 70 9
low 16 5

Let A denote the event that a disk has high shock resistance, and let B denote the event that a disk has high scratch resistance. If a disk is selected at random, determine the following probabilities. Input your answers in the fractional form (do not simplify).

P(A)=86/100

P(B)=79/100

P(A')=7/50

P(A U B)=95/100

P(A' U B)= ???

Respuesta :

Answer:

[tex]P(A'\cup B)=\frac{84}{100}[/tex]

Step-by-step explanation:

Let A and B represents the following events.

A denote the event that a disk has high shock resistance.

B denote the event that a disk has high scratch resistance.

Given probabilities:

[tex]P(A)=\frac{70+16}{100}=\frac{86}{100}[/tex]

[tex]P(B)=\frac{70+9}{100}=\frac{79}{100}[/tex]

[tex]P(A')=\frac{9+5}{100}=\frac{7}{50}[/tex]

[tex]P(A\cup B)=\frac{70+16+9}{100}=\frac{95}{100}[/tex]

The probability of intersection of A and B is,

[tex]P(A\cap B)=P(A)+P(B)-P(A\cup B)[/tex]

Substitute the above values.

[tex]P(A\cap B)=\frac{86}{100}+\frac{79}{100}-\frac{95}{100}=\frac{70}{100}[/tex]

The probability of union of A' and B is,

[tex]P(A'\cup B)=P(A')+P(A\cap B)[/tex]

Substitute the above values.

[tex]P(A'\cup B)=\frac{7}{50}+\frac{70}{100}[/tex]

[tex]P(A'\cup B)=\frac{14}{100}+\frac{70}{100}[/tex]

[tex]P(A'\cup B)=\frac{84}{100}[/tex]

Therefore, [tex]P(A'\cup B)=\frac{84}{100}[/tex].

Using Venn probabilities, it is found that the desired probability is given by:

[tex]P(A' \cup B) = \frac{21}{25}[/tex]

The or probability of Venn sets is given by:

[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]

In this problem, we want:

[tex]P(A' \cup B) = P(A') + P(B) - P(A' \cap B)[/tex]

We have that:

[tex]P(A') = \frac{7}{50}[/tex]

[tex]P(B) = \frac{79}{100}[/tex]

[tex]P(A' \cap B)[/tex] is probability of A not happening and B happening, thus low shock resistance and high scratch resistance, thus [tex]P(A' \cap B) = \frac{9}{100}[/tex]

Then

[tex]P(A' \cup B) = P(A') + P(B) - P(A' \cap B)[/tex]

[tex]P(A' \cup B) = \frac{7}{50} + \frac{79}{100} - \frac{9}{100}[/tex]

[tex]P(A' \cup B) = \frac{14}{100} + \frac{70}{100}[/tex]

[tex]P(A' \cup B) = \frac{84}{100}[/tex]

[tex]P(A' \cup B) = \frac{21}{25}[/tex]

A similar problem is given at https://brainly.com/question/23508811