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Illusion [34]
1 year ago
6

Suppose that the concentration of a bacteria sample is 100000 bacteria per milliliter. If the concentration doubles every 2 hour

s how long will it take for the concentration to reach 380000 bacteria per milliliter?
Mathematics
1 answer:
Aliun [14]1 year ago
4 0

Answer:

3.85 hours

Step-by-step explanation:

We have that the model equation in this case would be of the following type, being "and" the concentration of bacteria:

y = a * e ^ (b * t)

where a and b are constants and t is time.

We know that when the time is 0, we know that there are 100,000 bacteria, therefore:

100000 = a * e ^ (b * 0)

100000 = a * 1

a = 100000

they tell us that when the time is 2 hours, the amount doubles, that is:

200000 = a * e ^ (b * 2)

already knowing that a equals 100,000

e ^ (b * 2) = 2

b * 2 = ln 2

b = (ln 2) / 2

b = 0.3465

Having the value of the constants, we will calculate the value of the time when there are 380000, that is:

380000 = 100000 * (e ^ 0.3465 * t)

3.8 = e ^ 0.3465 * t

ln 3.8 = 0.3465 * t

t = 1.335 / 0.3465

t = 3.85

That is to say that in order to reach this concentration 3.85 hours must pass

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ad-work [718]

Answer:

1/8

Step-by-step explanation:

1/2= 4(1/2) = 4/8

4/8+3/8= 7/8

7/8 + 1/8 = 1

7 0
2 years ago
In each of Problems 5 through 10, verify that each given function is a solution of the differential equation.
WARRIOR [948]

Answer:

For First Solution: y_1(t)=e^t

y_1(t)=e^t is the solution of equation y''-y=0.

For 2nd Solution:y_2(t)=cosht

y_2(t)=cosht  is the solution of equation y''-y=0.

Step-by-step explanation:

For First Solution: y_1(t)=e^t

In order to prove whether it is a solution or not we have to put it into the equation and check. For this we have to take derivatives.

y_1(t)=e^t

First order derivative:

y'_1(t)=e^t

2nd order Derivative:

y''_1(t)=e^t

Put Them in equation y''-y=0

e^t-e^t=0

0=0

Hence y_1(t)=e^t is the solution of equation y''-y=0.

For 2nd Solution:

y_2(t)=cosht

In order to prove whether it is a solution or not we have to put it into the equation and check. For this we have to take derivatives.

y_2(t)=cosht

First order derivative:

y'_2(t)=sinht

2nd order Derivative:

y''_2(t)=cosht

Put Them in equation y''-y=0

cosht-cosht=0

0=0

Hence y_2(t)=cosht  is the solution of equation y''-y=0.

3 0
1 year ago
3. Standard deviation is ________. a mean of squared differences the square root of the variance unit-free the covariance 4. Sta
Ksenya-84 [330]

Answer:

3. Standard deviation is the square root of the variance.

4. Standard deviation is useful because it has the same units as the underlying data.

Step-by-step explanation:

3. In statistics, the dispersion in a given data with respect to its mean distribution can be determined or measured by standard deviation and variance. The standard deviation of a distribution can also be determined as the square root of variance.

4. Standard deviation is measured in the same units as that of the original data. Thus it has the same units as the underlying data.

5 0
1 year ago
Suppose two different methods are available for eye surgery. The probability that the eye has not recovered in a month is 0.002
umka21 [38]

Answer:

0.4007

Step-by-step explanation:

Let's define the following events:

A: method A is used

B: method B is used

NR: the eye has not recovered in a month

R: the eye is recovered in a month

The probability that the eye has not recovered in a month is 0.002 if method A is used, i.e., P(NR|A) = 0.002, so P(R|A) = 0.998.

When method B is used, the probability that the eye has not recovered in a month is 0.005, i.e., P(NR|B) = 0.005, so P(R|B) = 0.995.

40% of eye surgeries are done with method A, i.e., P(A) = 0.4

60% of eye surgeries are done with method B, i.e., P(B) = 0.6

If an eye is recovered in a month after surgery is done in the hospital, what is the probability that method A was performed? We are looking for P(A|R), then, by Bayes' Formula

P(A|R) = P(R|A)P(A)/(P(R|A)P(A) + P(R|B)P(B)) = 0.998*0.4/(0.998*0.4 + 0.995*0.6) = 0.4007

4 0
2 years ago
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Blizzard [7]

Answer:

Graph A

Step-by-step explanation:

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The big key here is the part " which graph shows the range of car rental rates that would be cheaper than the taxi service. " Our inequality must thus have the variable " c " on the same side as the payment for gas ($ 24 ), and must be less than the taxi service ( $ 128 ), or in other words a less than sign. Another point is the car rental rate. We know it stands for c, but it is dependent on the number of days. Hence we can conclude the following inequality,

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The graph that models this range should be the first one, option A. This graph is not accurate however, as it extends infinitely in the negative direction, and you can't have negative money, or rather be in debt - in this situation.

6 0
2 years ago
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