What is the domain and range?

katrin2010 [14]

The equation out of this is; what is 250/100 of a number x = 90?
=> Division of 250 by 100 gives 2.5.
=> Now multiply 2.5 by a number x resulting to 2.5x on the L.H.S.
=> make x the subject and come up with x = 90/2.5.
answer is 1/36.

4 0

3 years ago

Among persons donating blood to a clinic, 85% have Rh+ blood (that is, the Rhesus factor is present in their blood.) Six people

Leona [35]

Answer:

a) There is a 62.29% probability that at least one of the five does not have the Rh factor.

b) There is a 22.36% probability that at most four of the six have Rh+ blood.

c) There need to be at least 8 people to have the probability of obtaining blood from at least six Rh+ donors over 0.95.

Step-by-step explanation:

For each person donating blood, there are only two possible outcomes. Either they have Rh+ blood, or they do not. This means that we use the binomial probability distribution to solve this problem.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinatios of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

In this problem we have that:

$p = 0.85, n = 6$ .

a) fine the probability that at least one of the five does not have the Rh factor.

Either all six have the factor, or at least one of them do not. The sum of the probabilities of these events is decimal 1. So:

$P(X < 6) + P(X = 6) = 1$

$P(X < 6) = 1 - P(X = 6)$

In which:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

So

$P(X < 6) = 1 - P(X = 6) = 1 - 0.3771 = 0.6229$

There is a 62.29% probability that at least one of the five does not have the Rh factor.

b) find the probability that at most four of the six have Rh+ blood.

Either more than four have Rh+ blood, or at most four have. So

$P(X \leq 4) + P(X > 4) = 1$

$P(X \leq 4) = 1 - P(X > 4)$

In which

$P(X > 4) = P(X = 5) + P(X = 6)$

$P(X = 5) = C_{6,5}.(0.85)^{5}.(0.15)^{1} = 0.3993$

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

$P(X > 4) = P(X = 5) + P(X = 6) = 0.3993 + 0.3771 = 0.7764$

$P(X \leq 4) = 1 - P(X > 4) = 1 - 0.7764 = 0.2236$

There is a 22.36% probability that at most four of the six have Rh+ blood.

c) The clinic needs six Rh+ donors on a certain day. How many people must donate blood to have the probability of obtaining blood from at least six Rh+ donors over 0.95?

With 6 donors:

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

37.71% probability of obtaining blood from at least six Rh+ donors over 0.95.

With 7 donors:

$P(X = 6) = C_{7,6}.(0.85)^{6}.(0.15)^{1} = 0.3960$

0.3771 + 0.3960 = 0.7764 = 77.64% probability of obtaining blood from at least six Rh+ donors over 0.95.

With 8 donors

$P(X = 6) = C_{8,6}.(0.85)^{6}.(0.15)^{2} = 0.2376$

0.3771 + 0.3960 + 0.2376 = 1.01 = 101% probability of obtaining blood from at least six Rh+ donors over 0.95.

There need to be at least 8 people to have the probability of obtaining blood from at least six Rh+ donors over 0.95.

5 0

3 years ago

Please help me to answer this with solution.Please answer it correctly.

Bess [88]

Answer:

Eco friendly furniture is furniture that is created in a manner that has minimum negative impact on the environment. This means that where wood is used, it has come from renewable sources and any chemicals used in the process do not pollute or harm the environment. i think

Step-by-step explanation:

yes

8 0

3 years ago

Given f(x)= -4x-10 and f(x)=10. find x

yulyashka [42]

Answer:

x = - 5

Step-by-step explanation:

Given

f(x) = - 4x - 10 and f(x) = 10, the equate right sides, that is

- 4x - 10 = 10 ( add 10 to both sides )

- 4x = 20 ( divide both sides by - 4 )

x = - 5

4 0

3 years ago

I NEED HELP !!!!!!!!!!!!!!!!!!!!!

cricket20 [7]

you must substitute x in the equation given :)

examples:

when x is -2

therefore, y = 2(-2) + 3

y = -1

when x is 0

therefore, y = 2(0) + 3

y = 3

when x is 1

therefore, y = 2(1) + 3

y = 5

when x is 3

therefore, y = 2(3) + 3

y = 9

for (b) you only have to plot based on the table ;)

hope this helps

8 0

2 years ago