Ask question

Ask question

All categories

3 years ago

8

It is reported that the wild gorilla population has declined by 70% over the last 10 years. There are now 4,000 gorillas left in

the wild. To the nearest thousand, how many gorillas were there 10 years ago?

1 answer:

Cloud [144]3 years ago

3 0

I will try to get back to you a little later

You might be interested in

A veterinarian wants to know if pit bulls or golden retrievers have a higher incidence of tooth decay at the age of three. The v

BigorU [14]

Answer: B) [-0.0332,0.1332]

Step-by-step explanation: <u>Confidence</u> <u>Interval</u> is an interval where we can be a percentage sure the true mean is.

The confidence interval for a difference in population proportion is calculated following these steps:

First, let's find population proportion for each population:

$p_{1}=\frac{30}{120}=0.25$

$p_{2}=\frac{32}{160}=0.2$

Second, calculate standard deviation for each proportion:

$\sigma_{1}=\sqrt{\frac{0.25(0.75)}{120} } = 0.0395$

$\sigma_{2}=\sqrt{\frac{0.2(0.8)}{160} } = 0.0316$

Now, we calculate standard error for difference:

$SE=\sqrt{\sigma_{1}^{2}+\sigma_{2}^{2}}$

$SE=\sqrt{0.0395^{2}+0.0316^{2}}$

SE = 0.0505

The z-score for a 90% CI is 1.645.

Then, confidence interval is

$p_{1}-p_{2}$ ± z-score.SE

$0.25-0.2$ ± $1.645(0.0505)$

0.05 ± 0.0831

The limits of this interval are:

inferior: 0.05 - 0.0831 = $-0.0332$

superior: 0.05 + 0.0831 = 0.1332

The 90% confidence interval for the difference in the population proportion of pit pulls and golden retrievers is $[-0.0332,0.1332]$ .

8 0

3 years ago

Can someone help me with (Geometry)

igomit [66]

Step-by-step explanation:

I think the fig.. will helps you a lot...

7 0

3 years ago

What is the term for the price at which a car manufacturer recommends a vehicle should be sold?

Sergeu [11.5K]

MSRP is the term recomended by manufacturers.

6 0

3 years ago

Read 2 more answers

Which is the inverse of the function f(x)=1/3x+5 ?

PtichkaEL [24]

To find the inverse of a function, switch the x and the y and then solve for the new y. Like this: $x= \frac{1}{3}y+5$ . Subtract 5 from both sides to get $x-5= \frac{1}{3}y$ and then multiply both sides by 3. 3(x - 5) = y. B is your choice.

4 0

3 years ago

Read 2 more answers

When solving the following system by elimination, which variable would be eliminated after adding the 2 equations together?

drek231 [11]

Answer:

B. x

Step-by-step explanation:

-3x+8y=-6

3x-2y=-12

if we add these

-3x+3x+8y-2y=-6-12

6y=-12 so x will be eliminated

8 0

3 years ago