the mass of a ping pong ball is 2.3 grams. how many ping pong balls would it take to equal the mass of earth

PLEASE HELPPPPPP. I NEED IT DONEEEEE.

agasfer [191]

Answer:

1. Couples tickets: $8

Individual tickets: $4

2. Song download cost: $2

Movie download cost: $15

Step-by-step explanation:

You can solve both of these questions by doing system of equations.

Let's start with question 1.

There are 2 variables in this equation:

- Couples tickets price: let's represent these with the letter C

- Individual tickets price: let's represent these with the letter K

Writing the two equations would look this these:

5c + 2k = 48

3c + 2k = 32

Next, isolate a variable. I am going to isolate K in the first equation.

$2k = -5c + 48 \\k = -\frac{5}{2}c + 24$

Now that we isolated a variable we can plug that back in to the second equation:

$3c + 2(-\frac{5}{2}c + 24) = 32\\3c - \frac{10}{2}c + 48 = 32\\3c -5c + 48 = 32\\-2c + 48 = 32\\-2c = -16\\c = 8$

We found that c is equal to 8 so we can put that back in to an equation to solve for k.

5(8) + 2k = 48

40 + 2k = 48

2k = 8

k = 4

Therefore, the price for couples tickets is $8 and the price for individual tickets is $4.

Check #1:

5(8) + 2(4) = 48

40 + 8 = 48

48 = 48

3(8) + 2(4) = 32

24 + 8 = 32

32 + 32

Now, let's go on to question 2.

There are 2 variables in this equation:

- Price of songs downloaded: let's represent these with S

- Price of movies downloaded: let's represent these with M

Writing the two equations would look like this:

15s + 11m = 195

15s + 8m = 150

There is a simple way to answer this system, however.

If you change the bottom equations signs to negative you can minus the second equation from the first equation like this:

15s + 11m = 195

-(15s +8m = 150)

Minus them to get this equation:

3m = 45

Solve

m = 15

We have found that each movie download costs $15, now let's plug this back into an equation:

15s + 11(15) = 195

15s + 165 = 195

15s = 30

s = 2

Each song costs $2 to download.

Check #2:

15(2) + 11(15) = 195

30 + 165 = 195

195 = 195

15(2) + 8(15) = 150

30 + 120 = 150

150 = 150

I hope this helps!!

- Kay :)

6 0

3 years ago

10. Contacts. Assume that 30% of students at a university

jonny [76]

Using the normal distribution and the central limit theorem, we have that:

a) A normal model with mean 0.3 and standard deviation of 0.0458 should be used.

b) There is a 0.2327 = 23.27% probability that more than one third of this sample wear contacts.

<h3>Normal Probability Distribution</h3>

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

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

It 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, which is the percentile of X.

By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportion is approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1 - p)}{n}}$ , as long as $np \geq 10$ and $n(1 - p) \geq 10$ .