What is the measure of YB

Pleasantburg has a population growth model of P(t)=at2+bt+P0 where P0 is the initial population. Suppose that the future populat

Salsk061 [2.6K]

Answer: In June 2097

Step-by-step explanation:

According to the model, to find how many years t should take for $P(t)=21100$ we must solve the equation $0.9t^2+6t+14000=21100$ . Substracting 21100 from both sides, this equation is equivalent to $0.9t^2+6t-7100=0$ .

Using the quadratic formula, the solutions are $t_1= \frac{-6-\sqrt{6^2 -4*0.9*(-7100)}}{2*0.9}=-92.21$ and $t_2=\frac{-6+\sqrt{6^2 -4*0.9*(-7100)}}{2*0.9}=85.54$ . The solution $t_1=-92.21$ can be neglected as the time t is a nonnegative number, therefore $t=t_2=85.54$ .

The value of t is approximately 85 and a half years and the initial time of this model is the January 1, 2012. Adding 85 years to the initial time gives the date January 2097, and finally adding the remaining half year (six months) we conclude that the date is June 2097.

6 0

3 years ago

Three prime numbers that can be multiplied to get 825

Leona [35]

Answer:

Prime factorization: 825 = 3 × 5 × 5 × 11, which can be written 825 = 3 × 5² × 11.

Step-by-step explanation:

Hope this helps!

5 0

2 years ago

Read 2 more answers

How to factor 6x^2+7x-10

Studentka2010 [4]

the answer is....

(6x-5) (x+2)

6 0

3 years ago

Read 2 more answers

2(z – 10) = -4 (ignore this)

sukhopar [10]

2(z-10)=-4
2z-20=-4
2z=16
z=8

3 0

3 years ago

Read 2 more answers

Professor Doom has applied to the town planning board to build a Villain's Lair in a suburban neighborhood. The local residents

tester [92]

Answer:

Check explanation below.

Step-by-step explanation:

Hello!

The objective of this experiment is to test if doctor Doom is controlling the neighbors' minds from his new Lair. To test this a random sample of 11 neighbors was taken and a "free will" test was administrated before the Villain's Lair was constructed and again after it was finished.

This experiment type where you have a single sample and the variable is measured "before" and "after" applying a treatment (in this case, that doctor Doom has moved into town) is a classic example of a paired sample test. You have two dependent variables, X₁: "Results of the free will test before Dr. Doom Lair is constructed" and X₂: "Results of the free will test after Dr. Doom Lair is constructed", with these variables you can establish a new variable, Xd, that I'll define as " X₁- X₂", and the objective of my hypothesis test will be to know if there is any change after the Lair is done, if there is, in fact, a change then the population mean of the difference will be nonzero, symbolically: μd ≠ 0

Using the data I've calculated the summary measures for Xd:

sample mean: Xd[bar]= 3.18

sample standard deviation: Sd= 5.44

The statistic hypothesis is:

H₀: μd = 0

H₁: μd ≠ 0

α: 0.05

(There is no signification level specified, so I've chosen the most common one)

Assuming that the variable difference, Xd, has a normal distribution, and with unknown population variance, the best statistic to use is the Students-t for paired samples:

t= Xd[bar] - μd ~t $_{n-1}$

Sd/√n

This test is two-tailed, so you will reject at low values of the statistic or at high values of it.

$t_{n-1;\alpha/2 } = t_{10; 0.025} = -2.228$

$t_{n-1; 1-\alpha /2} = t_{10; 0.975} = 2.228$

If t ≤ -2.228 or t ≥ 2.228 then you reject the null hypothesis.

If -2.228 < t < 2.228 then you don't reject the null hypothesis.

t= Xd[bar] - μd = 3.18 - 0 = 1.94

Sd/√n 5.44/√11

Since the statistic value t= 1.94 then the decision is to not reject the null hypothesis.

So, with a significance level of 5% there is not enough evidence to reject the null hypothesis, this means that the population mean of the difference on the free will test results of the neighbors before and after the Villain's Lair was constructed is equal to cero. In other words, there is not enough evidence to conclude that Dr. Doom is controlling the neighbor's minds.

I hope it helps!

3 0

2 years ago