If x= 4, what is the value of 8x + 15? OA. 47 B. 52 C. 92 D. 152

Of 150 adults selected randomly from one town, 30 of them smoke. Construct a 99% confidence interval for the true percentage of

anyanavicka [17]

Answer:

The 99% confidence interval for the true percentage of all adults in the town that smoke is (0.1159, 0.2841).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence interval $1-\alpha$ , 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:

Of 150 adults selected randomly from one town, 30 of them smoke. This means that $n = 150, p = \frac{30}{150} = 0.2$

99% confidence interval

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.20 - 2.575\sqrt{\frac{0.20*0.80}{150}} = 0.1159$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.20 + 2.575\sqrt{\frac{0.20*0.80}{150}}{119}} = 0.2841$

The 99% confidence interval for the true percentage of all adults in the town that smoke is (0.1159, 0.2841).

3 0

3 years ago

Find the value of y when x equals 18. x - 7y= -17

galina1969 [7]

Answer:

y = 5

Step-by-step explanation:

Step 1:

(18) -7y = -17

-18 -18

Step 2:

-7y = -35

÷-7 ÷-7

y = 5

5 0

3 years ago

tressa's home is 4/5 mile from school. anton's home is 3/5 mile from school. how many times the distance from anton's home to sc

WINSTONCH [101]

The distance from Tressa's home to school is $1\frac{1}{3}$ times the distance from Anton's home to school

From the question,

Tressa's home is 4/5 mile from school

and Anton's home is 3/5 mile from school.

To determine how many times the distance from Anton's home to school is the distance from Tressa's home to school, we will divide the distance from Tressa's home to school by the distance from Anton's home to school

That is, 4/5 mile ÷ 3/5 mile

∴ we get

$\frac{4}{5} \div \frac{3}{5}$