1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
SpyIntel [72]
3 years ago
10

There are 70,000 bacteria present in a culture. An antibiotic is introduced to the culture and the number of bacteria is reduced

by half every 4 hours. Which of the following statements are true? Select all that apply

Mathematics
1 answer:
Harlamova29_29 [7]3 years ago
6 0

Answer:

24 hours after the antibiotic is introduced, the number of bacteria in the culture is reduced to 1093; The amount of bacteria present in the culture during the 24 hours after the antibiotic is introduced is an example of exponential decay; The function B(x) = 70000(0.5)ˣ, where x represents the number of 4 hour periods, represents the amount of bacteria present after the antibiotic is introduced.

Step-by-step explanation:

In any situation where an amount grows or declines by a set percent every time period can be represented using an exponential function.  Since the amount of bacteria is reduced by half, or 50%, every 4 hours, this is exponential decay.

Exponential functions such as this are of the form

y = a(1+r)ˣ, where a represents the initial population, r is the percent of growth or decrease, and x is the number of time periods.  In this situation, the initial population, a, is 70000.  Since the number of bacteria decreases by half, r = -0.50.  This gives us

y = 70000(1+-0.50)ˣ, or y = 70000(0.50)ˣ.

In 24 hours, there are 6 4-hour periods.  This means x = 6; this gives us

y = 70000(0.50)⁶ = 1093.75.

You might be interested in
Given a mean of 150 and a standard deviation of 25:
pishuonlain [190]
We have to define an interval about the mean that contains 75% of the values. This means half of the values will lie above the mean and half of the values lie below the mean.

So, 37.5% of the values will lie above the mean and 37.5% of the values lie below the mean.

In a Z-table, mean is located at the center of the data. So the position of the mean is at 50% of the data. So the position of point 37.5% above the mean will be located at 50 + 37.5 = 87.5% of the overall data

Similarly position of the point 37.5% below the mean will be located at 
50 - 37.5% = 12.5% of the overall data

From the z table, we can find the z value for both these points. 12.5% converted to z score is -1.15 and 87.5% converted to z score is 1.15.

Using these z scores, we can find the values which contain 75% of the values about the mean.

z score of -1.15 means 1.15 standard deviations below the mean. So this value comes out to be:

150 - 1.15(25) = 121.25

z score of 1.15 means 1.15 standard deviations above the mean. So this value comes out to be:

150 + 1.15(25) = 178.75

So, the interval from 121.25 to 178.75 contains the 75% of the data values. 
4 0
3 years ago
The editor of a textbook publishing company is deciding whether to publish a proposed textbook. Information on previous textbook
kogti [31]

Answer:

34.86% probability that it will be huge​ success

Step-by-step explanation:

Bayes Theorem:

Two events, A and B.

P(B|A) = \frac{P(B)*P(A|B)}{P(A)}

In which P(B|A) is the probability of B happening when A has happened and P(A|B) is the probability of A happening when B has happened.

In this question:

Event A: Receiving a favorable review.

Event B: Being a huge success.

Information on previous textbooks published show that 20 % are huge​ successes

This means that P(B) = 0.2

99 % of the huge successes received favorable​ reviews

This means that P(A|B) = 0.99

Probability of receiving a favorable review:

20% are huge​ successes. Of those, 99% receive favorable reviews.

30% are modest​ successes. Of those, 70% receive favorable reviews.

30% break​ even. Of those, 40% receive favorable reviews.

20% are losers. Of those, 20% receive favorable reviews.

Then

P(A) = 0.2*0.99 + 0.3*0.7 + 0.3*0.4 + 0.2*0.2 = 0.568

Finally

P(B|A) = \frac{P(B)*P(A|B)}{P(A)} = \frac{0.2*0.99}{0.568} = 0.3486

34.86% probability that it will be huge​ success

4 0
3 years ago
This one-dimensional figure goes on forever in two directions.
Vesna [10]
Please mark me Brainliest!

It should be B. line because line segment has a end and a Ray can only go in one direction forever while a line can go both directions forever.

Hope this helps!
5 0
2 years ago
Read 2 more answers
I'm stuck idkdmsjshhdhd
Klio2033 [76]
I hope this helps you



1)


a) 18/50


b) 6.1/3=2


c) 9/2.8/3=3.4=12


2)


1 1/2=1.2+1/2=3/2


3 3/4=3.4+3/4=15/4



if we can 12 muffins with 3/2 cups


how many muffins with 15/4


?.3/2=12.15/4


?=30 muffins


3 0
3 years ago
Mason borrowed 1,200 from a friend to buy a new hot tub, His friend does't charge any interest and mason makes 50 payments eavh
balu736 [363]
You can identify the slope and y-intersept. The slope is 50 and the y-intercept is (0, 1200). You could also do the x-intercept, which would be the number of months passed when he pays off the debt fully. The x intercept would be (24,0)
5 0
3 years ago
Other questions:
  • I need help. Tell me ALL you know
    15·1 answer
  • What number is 20% of 625
    6·2 answers
  • What is the surface area of the figure shown ?
    14·1 answer
  • The cost, ox), for a taxi ride is given by o(x) = 3x + 2.00, where x is the
    6·1 answer
  • Which estimate best describes the area under the curve in square
    14·1 answer
  • Help !! help !! help !!
    13·1 answer
  • Find the slope of the line and that passes through (7, 2) and (-7, 48)
    6·1 answer
  • How do i solve this?​
    12·1 answer
  • Pete's blueprint shows a layout of a house. Every 6 inches in the blueprint represents 1.5 feet of the actual house. What are th
    13·1 answer
  • What is the simplest form of the radical expressio √48x^4y^3? Assume x and y are positive.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!