Using the definition of a rectangle, the left vertical side measure is 7 and right vertical side is 6. So the missing legs of the triangle is 4 and 3.

Apply triangle formula, base x height divided by 2.

$\frac{4 \times 3}{2} = 6$

Area of rectangle is length x width so the area is

$7 \times 6 = 42$

Subtract 6 from 42.

$42 - 6 = 36$

3 0

3 years ago

Researchers ask a random sample of 1,001 adults nationwide whether they favor or oppose the legalization of marijuana. Fifty-fiv

natima [27]

Answer:

b. It will decrease by a factor of 2

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 $1 - \frac{\alpha}{2}$ .

The lower end of the interval is given by:

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

The upper end of the interval is given by:

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

The length of the interval is the subtraction of the upper end by the lower end, so it is:

$L = 2z\sqrt{\frac{\pi(1-\pi)}{n}}$

This means that the length is inverse proportional to the square root of the size of the sample.

So, if the sample size is multiplied by 4, the length of the interval is going to decrease by a factor of 2.

4 0

3 years ago

Why do you divide by 60 after calculating the area of the trapezoid (to calculate the distance)? I got 900 but I don’t know why

Free_Kalibri [48]

Answer:

Step-by-step explanation:

What you are trying to do is a nice way to solve this problem. Without knowing any physics, you are using what math you know to get the answer. You are actually very close to being correct, and you are right. You do have to divide by 60.

Here's why and it is the one bit of physics you have to know.

The speed is km/hour. That word hour is the culprit. Your time is in minutes and you have to get it into hours. In physics, the units have to be consistent.

So ...

b1 = 19 minutes which is 19 min [1 hour / 60 minutes] = 19/60 = 0.31667 hour

b2 = 26 minutes which is 26 min [ 1 hour/60 minutes] = 26/60 = 0.4333 hour

h = 40 km/hour

Area = (0.31667 hour + 0.4333 hour)*40 km/hour /2

Area = 0.75 hour * 40 km/hr //2

Area = 15 km

6 0

4 years ago