[PLEASE HELP! 49 POINTS PER ANSWER!]

A diagnostic test for a disease is such that it (correctly) detects the disease in 90% of the individuals who actually have the

Ne4ueva [31]

Answer:

0.2177 = 21.77% conditional probability that she does, in fact, have the disease

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

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

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Test positive

Event B: Has the disease

Probability of a positive test:

90% of 3%(has the disease).

1 - 0.9 = 0.1 = 10% of 97%(does not have the disease). So

$P(A) = 0.90*0.03 + 0.1*0.97 = 0.124$

Intersection of A and B:

Positive test and has the disease, so 90% of 3%

$P(A \cap B) = 0.9*0.03 = 0.027$

What is the conditional probability that she does, in fact, have the disease

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.027}{0.124} = 0.2177$

0.2177 = 21.77% conditional probability that she does, in fact, have the disease

3 0

3 years ago

There were 4 crates of 18 peaches each all the peaches were put into 3 boxes equally how many peaches were there in each box

PIT_PIT [208]

6 peaches were there in each box

Solution:
18/3 = 8

5 0

3 years ago

what is 9z+2=6z-10-z-4 we have to do something called railroad tracks where we put lines down the sides of the equal sign but I

Colt1911 [192]

You want to solve for 'z'.
First combine like terms on either side of the equal sign.

Left side: 9z +2 ----> No like terms, leave alone

Right side: 6z - 10 -z - 4 ----> circle like terms and add
6z -z = 5z
-10 -4 = -14
Now the equation is:
9z + 2 = 5z - 14

Get all the 'z' terms on the left side and all the numbers on right side.
You can move a term to the other side if you flip the sign.

Move 5z to left side, flip the sign to -5z
Move '2' to right side, flip the sign to -2

9z - 5z = -2 -14

Add like terms
4z = -16

Divide by 4 on both sides
z = -4

3 0

3 years ago

25. A sequence of positive integers with 2020 terms is called an FT sequence if each term

lana66690 [7]

Answer:

The first term in the sequence is odd-valued and so there are m choices for it.2020 Gauss Contest Solutions Page 19

The second term in the sequence is even-valued and so there are m − 1 choices for it.

Thus, there are a total of m × (m − 1) FT sequences that begin with an odd-valued term

followed by an even-valued term.

Finally, we consider the FT sequences that begin with an even-valued term followed by an

odd-valued term (Parity #4).

Again, there are exactly twice as many odd-valued terms as there are even-valued terms in the

first 2019 terms (since the pattern repeats even, odd, odd).

However in this case, the 2020th term is even and so there are fewer than twice as many odd valued terms as there are even-valued terms.

Thus, there are m2 + m × (m − 1) FT sequences that satisfy the required conditions.

Since there are 2415 such FT sequences, we may solve m2 + m × (m − 1) = 2415 by trial and

error.

Evaluating m2 + m × (m − 1) when m = 30, we get 302 + 30 × 29 = 1770, and so m is greater

than 30.

When m = 33, we get 332 + 33 × 32 = 2145.

When m = 34, we get 342 + 34 × 33 = 2278.

When m = 35, we get 352 + 35 × 34 = 2415, as required.

Answer: (D)

Step-by-step explanation:

8 0

3 years ago

During a bike challenge, riders have to collect various colored ribbons. Each 1/2 mile they collect a red ribbon, each 1/8 mile

Oliga [24]

One red ribbon, 6 green ribbons and 3 blue ribbons total together would be 10 ribbons

3 0

3 years ago