2. Suppose that four times the square of a number equals 20 times that num-

Write 17/25 as a percent

WINSTONCH [101]

Answer:

68%

Step-by-step explanation:

Times both the top and bottom number by 4.

6 0

4 years ago

Read 2 more answers

Does 22 7, -3, 217, 16 5, or -4.5 come first when the numbers are listed from least to greatest? Explain. Answer ASAP

kvasek [131]

-4.5 will come first

3 0

3 years ago

The figure below shows circle with center O and two perpendicular diameters

dlinn [17]

Answer:

Triangles OAB,BOC,COD,DOA are isocele and right , are thus equals and have the same hypothenus . The quadrilater ABCD is a diamond (having 4 sides equals) and its diagonals perpendicular is thus a square.

Step-by-step explanation:

3 0

3 years ago

What is the probability that a random person who tests positive for a certain blood disease actually has the disease, if we know

xeze [42]

Answer:

Step-by-step explanation:

Hello!

Any medical test used to detect certain sicknesses have several probabilities associated with their results.

Positive (test is +) ⇒ P(+)

True positive (test is + and the patient is sick) ⇒ P(+ ∩ S)

False-positive (test is + but the patient is healthy) ⇒P(+ ∩ H)

Negative (test is -) ⇒ P(-)

True negative (test is - and the patient is healthy) ⇒ P(- ∩ H)

False-negative (test is - but the patient is sick) ⇒ P(- ∩ S)

The sensibility of the test is defined as the capacity of the test to detect the sickness in sick patients (true positive rate).

⇒ P(+/S) = P(+ ∩ S)

P(S)

The specificity of the test is the capacity of the test to have a negative result when the patients are truly healthy (true negative rate)

⇒ P(-/H) = P(- ∩ H)

P(H)

For this particular blood disease the following probabilities are known:

1% of the population has the disease: P(S)= 0.01

95% of those who are sick, test positive for it: P(+/S)= 0.95 (sensibility of the test)

2% of those who don't have the disease, test positive for it: P(+/H)= 0.02

The probability of a person having the blood sickness given that the test was positive is:

P(S/+)= P(+ ∩ S)

P(+)

The first step you need to calculate the intersection between both events + and S, for that you will use the information about the sickness prevalence in the population and the sensibility of the test:

P(+/S) = P(+ ∩ S)

P(S)

P(+/S)* P(S) = P(+ ∩ S)

P(+ ∩ S) = 0.95*0.01= 0.0095

The second step is to calculate the probability of the test being positive:

P(+)= P(+ ∩ S) + P(+ ∩ H)

Now we know that 1% of the population has the blood sickness, wich means that 99% of the population doesn't have it, symbolically: P(H)= 0.99

Then you can clear the value of P(+ ∩ H):

P(+/H) = P(+ ∩ H)

P(H)

P(+/H)*P(H) = P(+ ∩ H)

P(+ ∩ H) = 0.02*0.99= 0.0198

Next you can calculate P(+):

P(+)= P(+ ∩ S) + P(+ ∩ H)= 0.0095 + 0.0198= 0.0293

Now you can calculate the asked probability:

P(S/+)= P(+ ∩ S) = 0.0095 = 0.32

P(+) 0.0293

I hope it helps!

6 0

3 years ago

Laura drove 638 miles in 11 hours at the same rate how long would it take her to drive 406 miles

shusha [124]

Answer:

Step-by-step explanation:

This is a d = rt problem; but since it is linear, then proportions will work too. Set up the proportion with miles on top and hours on the bottom:

$\frac{miles}{hrs}:$

Then put the numbers in where they go, keeping in mind that miles goes with miles and hours goes with hours in the ratios, and that our unknown is time (hours):

$\frac{miles}{hrs}:\frac{638}{11}=\frac{406}{x}$ and cross multiply to solve:

638x = 4466 so

x = 7 hrs

6 0

3 years ago