In the figure, angle E measures 30°, angle F measures 57°, and angle B measures 27°. What is the measurement of angle A?

nikdorinn [45]

horizontal shrink by a factor of 1/2

4 units to the left

8 0

3 years ago

A programmer plans to develop a new software system. In planning for the operating system that he will use, he needs to estimat

Vedmedyk [2.9K]

Using the z-distribution, we have that:

a) A sample of 601 is needed.

b) A sample of 93 is needed.

c) A. Yes, using the additional survey information from part (b) dramatically reduces the sample size.

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

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

In which z is the z-score that has a p-value of $\frac{1+\alpha}{2}$ .

The margin of error is:

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

95% confidence level, hence $\alpha = 0.95$ , z is the value of Z that has a p-value of $\frac{1+0.95}{2} = 0.975$ , so $z = 1.96$ .

For this problem, we consider that we want it to be within 4%.

Item a:

The sample size is <u>n for which M = 0.04.</u>

There is no estimate, hence $\pi = 0.5$

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

$0.04 = 1.96\sqrt{\frac{0.5(0.5)}{n}}$

$0.04\sqrt{n} = 1.96\sqrt{0.5(0.5)}$

$\sqrt{n} = \frac{1.96\sqrt{0.5(0.5)}}{0.04}$

$(\sqrt{n})^2 = \left(\frac{1.96\sqrt{0.5(0.5)}}{0.04}\right)^2$

$n = 600.25$

Rounding up:

A sample of 601 is needed.

Item b:

The estimate is $\pi = 0.96$ , hence:

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

$0.04 = 1.96\sqrt{\frac{0.96(0.04)}{n}}$

$0.04\sqrt{n} = 1.96\sqrt{0.96(0.04)}$

$\sqrt{n} = \frac{1.96\sqrt{0.96(0.04)}}{0.04}$

$(\sqrt{n})^2 = \left(\frac{1.96\sqrt{0.96(0.04)}}{0.04}\right)^2$

$n = 92.2$

Rounding up:

A sample of 93 is needed.

Item c:

The closer the estimate is to $\pi = 0.5$ , the larger the sample size needed, hence, the correct option is A.

For more on the z-distribution, you can check brainly.com/question/25404151

8 0

2 years ago

What is the following product?<br> 3 square root of 5 • square root of 2

evablogger [386]

The answer is 6√200, or on edge.

5 0

3 years ago

-8.0 is classified as?Select all that apply * Natural Number Whole Number Integer Rational Number

grigory [225]

Answer:

Integer and Rational Number

Step-by-step explanation:

Natural numbers are positive numbers starting at 1 and going onward. Since -8.0 is not a positive number, it is not a natural number.

Whole numbers are natural numbers and 0 altogether. -8 is not greater than zero or positive, so it is not a whole number.

A rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number. -8.0 can also be written as -8/1, so it is a rational number and an integer, since every integer is a number over 1 and also a rational number.

7 0

3 years ago

The distance on the map between Yappy city and Quiet city is 23 cm.

jekas [21]

The actual distance between Yappy city and Quiet city when it is 23 cm in map is 9.2 miles.

What is scaling ?

It is the technique to resize drawing with comparing to actual size of object which uses proportion or ratio. For example, Mapping of earth, drawing prototype of automobiles.

It is given that :

The distance on the map between Yappy city and Quiet city is 23 cm

and,

5cm = 2 miles

now, for 1 cm on map it is equal to 2/5 miles of actual distance.

Therefore to find the actual distance of 23 cm in map we simply multiply 23 with 2/5 :

actual distance :

2/5 x 23 = 9.2 miles

Therefore, the actual distance between Yappy city and Quiet city is 9.2 miles.