I need help on this ASAP!!

VLD [36.1K]

1. Collect like terms

(n - 0.3n) + (4.5 - 3)

2. Simplify

0.7n + 1.5

Final Answer:

0.7n + 1.5

7 0

2 years ago

certain virus infects one in every 300 people. A test used to detect the virus in a person is positive 80% of the time if the pe

Alekssandra [29.7K]

Answer:

The probability that a person has the virus given that they have tested positive is P(A|B)=0.032.

The probability that a person does not have the virus given that they have tested negative is P(A'|B')=0.999.

Step-by-step explanation:

a) The probability of B: "the person tests positive" is the sum of:

- The probability that a person has the virus and the test is positive.

$P(A) \cdot P(B|A)$

- The probability that a person don't have the virus but the test is positive.

$P(not \,A) \cdot P(B|not\,A)$

Then, the probability of B: "the person tests positive" is

$P(A|B)=\frac{P(B|A)}{P(B)}=\frac{P(A)\cdot P(B|A)}{P(A)\cdot P(B|A)+P(A')\cdot P(B|A')}$

We have

$P(A)=1/300=0.0033\\\\P(A')=1-P(A)=0.9967\\\\P(B|A)=0.8\\\\P(B|A')=0.08$

Then

$P(A|B)=\frac{P(A)\cdot P(B|A)}{P(A)\cdot P(B|A)+P(A')\cdot P(B|A')}\\\\P(A|B)=\frac{0.0033*0.8}{0.0033*0.8+0.9967*0.08}= \frac{0.00264}{0.00264+0.07974}=\frac{0.00264}{0.08238}= 0.032$

The probability that a person has the virus given that they have tested positive is P(A|B)=0.032.

b) The probability P(A'|B') is

$P(A'|B')=\frac{P(B'|A')\cdot P(A')}{P(B'|A')\cdot P(A')+P(B'|A)\cdot P(A)}$

We have

$P(A)=0.0033\\\\P(A')=1-P(A)=0.9967\\\\P(B'|A)=1-0.8=0.2\\\\P(B'|A')=1-0.08=0.92$

Then

$P(A'|B')=\frac{P(B'|A')\cdot P(A')}{P(B'|A')\cdot P(A')+P(B'|A)\cdot P(A)}=\frac{0.92*0.9967}{0.92*0.9967+0.2*0.0033}= \frac{0.917}{0.917+0.00066}= 0.999$

The probability that a person does not have the virus given that they have tested negative is P(A'|B')=0.999.

5 0

3 years ago

For each expression, use a property to write an equivalent expression. for ab

antiseptic1488 [7]

Would use commutative property

ab = a*b = b*a = ba

equivalent expression = ba

4 0

3 years ago

F(2) = 4(2)² +4 (2) -2

zloy xaker [14]

Answer:

22

Step-by-step explanation:

4(2)² + 4(2) - 2

Use PEMDAS, which is Parenthesis, Exponent, Multiplication, Division, Addition, Subtraction. In that order we evaluate.

Exponents first, since there is nothing else to do in the parenthesis.

4(2)² + 4(2) - 2

4(4) + 4(2) - 2

Next is Multiplication and Division

4(4) + 4(2) - 2

16 + 8 - 2

Lastly are Addition and Subtraction

16 + 8 - 2

16 + 6

22

5 0

2 years ago

Kalel says that 24 ÷5 equals 36 ÷8 because both are “4 R4”. Show his mistake using decimal division.

Daniel [21]

Answer:

Kalels weight gain - I really feel for you :( We all know how that feels but eating animals is not going to help you lose the weight.)

Step-by-step explanation:

jk

6 0

2 years ago