Answer:
C
Step-by-step explanation:
The number of people who have heard a rumor is modeled by the logistic function:
And we want how many days has passed since the rate at which the rumor spread began to decrease.
First, the numerator tells us that the total number of people who will have heard the rumor by the end is 260.
Recall that the point of maximum growth is always half of the maximum capacity.
In this case, that point will be 260/2 = 130.
For a logistic function, the rate of all values to the left of the halfway point is increasing, (i.e. concave up), while the rate of all values to the right is decreasing (i.e. concave down). Therefore, we can solve for x when f(x) = 130:
Cross-multiply:
Distribute:
Solving for x:
Therefore:
Taking the natural log of both sides:
Therefore:
After about 52.3 days, the rate at which the rumor started spreading will begin to decrease.
The lower and upper limit of the 95% confidence interval is 183.2 and 196.0 unit.
What is a confidence interval ?
When you run your experiment again or resample the population in the same way, you can expect your estimate to fall within a certain range of values a certain percentage of the time. This is known as the confidence interval.
Main Body:
Given in question :
x- bar = 189.6
standard deviation = 10
C.I. = 95% =0.95
N=12
so, degree of freedom (D.F) = N-1 = 11
confidence level (α) = (1- C.I.)/2
= 0.025
according to t- distribution table for d.f = 11 and α= 0.025 , my result is 2.201
Now dividing standard deviation by square root of samples, we get
= 10/√12= 2.887
Lower limit = Mean - 2.201*2.887
= 189.6- 6.354
= 183.246
Upper limit = Mean + 2.201*2.887
= 189.6 + 6.354
= 195.954
Hence the result is 183.2 and 196.
to learn more about confidence interval , visit;
brainly.com/question/15712887
#SPJ13
Answer: 16.5
Step-by-step explanation:
Original price is 22 remove 25% by multiplying 22 by 0.75
If trying to find the original price when the discount is 25% and the discounted price is 22 take 22 and divide it by 3 and then multiply it by 4