In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 185, \pi = \frac{100}{185} = 0.5405$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5405 - 1.96\sqrt{\frac{0.5405*0.4595}{185}} = 0.4687$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5405 + 1.96\sqrt{\frac{0.5405*0.4595}{185}} = 0.6123$

The 95% confidence interval for the true proportion of bottlenose dolphin signature whistles that are type a whistles is (0.4687, 0.6123).

3 0

3 years ago

Pls help me with this

ValentinkaMS [17]

I don’t see anything

6 0

3 years ago

Which exponential function goes through the points (1,8) and (4,64)?

vova2212 [387]

Plug in (4,64) into each answer choice.

A) 4(2)^x
64 =4(2)^4
64 = 4(16)
64 = 64

Answer choice A is correct.

B) f(x) = 2(4)^x
64 = 2(4)^4
64 = 2(256)
64 ≠ 512

Answer choice B is incorrect.

C) f(x) = 4(2)^{-x}
64 = 4(2)^{-4}
64 = 4(-0.0625)
64 ≠ 0.25

Answer choice C is incorrect.

D) f(x) = 2(4)^{-x}
64 = 2(4)^{-4}
64 = 2(0.00390625)
64 ≠ 0.0078125

Answer choice D is incorrect.

Your answer is B<span>) f(x)=2(4)^x</span>

4 0

3 years ago