A. A parallelogram has a base of 9 units and a corresponding height of ſ units. What is its area?

There are 30 students in a class that took a test. The average grade of 10 students was 80. The other 20 students average was 89

Vsevolod [243]

10 students averaged 80, so the sum of their scores was (10 x 80) = 800

20 students averaged 89, so the sum of their scores was (20 x 89) = 1,780

All together, the sum of all 30 scores was (800 + 1,780) = 2,580

30 students totaled 2,580, so their average was (2,580 / 30) = <em> 86</em> .

6 0

3 years ago

the north pole is in the middle of the ocean. A person at sea level at the north pole would be 3,949 miles from the center of th

musickatia [10]

Answer:

7,897.30 miles

Step-by-step explanation:

It is given that the North Pole is at a distance of 3,949 miles from the center of the earth.

We also know that the sea floor is below 2.4 miles from the sea level.

It is given that a submarine is located at the sea floor near North Pole. Hence, the distance of the submarine from the center of the earth would be

3949 - 2.4 = 3946.6 miles.

On the other hand, the South Pole is given to be at an elevation of 1.7 miles from the sea level.

Since we know that the sea level is at a distance of 3949 miles from the center of the earth, we can immediately calculate the distance of the South Pole from the center of the earth to be

3949 + 1.7 = 3950.7 miles.

Putting all of this together, we see that the center of the earth is at a distance of 3946.6 miles from the submarine near the North Pole, and the center of the earth in turn is 3950.7 miles from the South Pole.

Hence, the distance between the submarine and a person on the South Pole = 3946.6 + 3950.7 = 7897.3 miles.

6 0

4 years ago

Jill sold half of her comic books and then bought sixteen more. She now has 36. With how many did she begin?

Alex777 [14]

Answer:

$\frac{1}{2}x + 16 = 36$

40 comic books

Step-by-step explanation:

Let x be the Jill comic books.

Given:

Jill sold half of her comic books and then bought sixteen more. She now has 36.

$\frac{1}{2}\ (Jill\ books) + 16\ more\ books = 36$

$\frac{1}{2}\ (x) + 16 = 36$

$\frac{1}{2}x + 16 = 36$

Therefore the algebraic equation of the given statement.

$\frac{1}{2}x + 16 = 36$ --------(1)

Now we solve above equation for x.

Subtract by 16 both side of the equation 1.

$\frac{1}{2}x + 16 -16 = 36 -16$

$\frac{1}{2}x = 20$

Multiply by 2 both side of the above equation.

$2\times \frac{1}{2}x =2\times 20$

$x = 40$

Therefore, Jill had 40 comic books.

8 0

3 years ago

PLS ANSWER !!!! <br><br> what is the formula when finding the slope given in two ordered pairs

Katarina [22]

Answer: Since you already know that the ordered pair is in the format of (x, y), then you can label one of the ordered pairs as 1 and kind of distribute it to get 1(x, y) = (x-sub1, y-sub1). Then just use the slope formula (y2-y1)/(x2-x1).

Step-by-step explanation:

5 0

4 years ago

The lengths of pregnancies are normally distributed with a mean of days and a standard deviation of days. a. Find the probabilit

Alik [6]

Answer:

a) The probability of a pregnancy lasting X days or longer is given by 1 subtracted by the p-value of $Z = \frac{X - \mu}{\sigma}$ , in which $\mu$ is the mean and $\sigma$ is the standard deviation.

b) We have to find X when Z has a p-value of $\frac{a}{100}$ , and X is given by: $X = \mu - Z\sigma$ , in which $\mu$ is the mean and $\sigma$ is the standard deviation.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

In this question:

Mean $\mu$ , standard deviation $\sigma$

a. Find the probability of a pregnancy lasting X days or longer.

The probability of a pregnancy lasting X days or longer is given by 1 subtracted by the p-value of $Z = \frac{X - \mu}{\sigma}$ , in which $\mu$ is the mean and $\sigma$ is the standard deviation.

b. If the length of pregnancy is in the lowest a%, then the baby is premature. Find the length that separates premature babies from those who are not premature.

We have to find X when Z has a p-value of $\frac{a}{100}$ , and X is given by: $X = \mu - Z\sigma$ , in which $\mu$ is the mean and $\sigma$ is the standard deviation.

8 0

3 years ago