What is the equation for the tangent plane of a surface?

A group of friends went out for dinner and decided to split the cost of the bill equally. If each person contributed $32, the fr

lianna [129]

Answer:

The number of friends that went out for dinner is 8

And their bill is $238

Step-by-step explanation:

Let's assume that the number of friends that went out for dinner to be x

And the bill for the dinner to be y

If each person contributed $32 and paid off the bill,they will have a balance of $18

32x - 18 = y_____equation 1

If each person contributed $35 and paid off the bill and also 15% tip,they will have a balance of $6.30

35x - 6.3 = y + (15% of y)

35x - 6.3 = y + (3y/20)

Open up the bracket

35x - 6.3 =(20y + 3y)/20

700x - 126 = 23y______equation 2

From equation 1,y = 32x - 18

Put the above in equation 2 and we have

700x - 126 = 23(32x -18)

700x - 126 = 736x - 414

collect like terms

36x = 288

x = 288/36

x = 8

Remember that equation 1 says that y = 32x - 18 and we now know that x = 8 .

Substitute and we have

(32 × 8) - 18

y = 238

The number of friends that went out for dinner is 8

And their bill is $238

3 0

3 years ago

If the moon is approximately 3.63*10/8 meters from earth what is 3.63*10/8 in standard Notation

disa [49]

Move the decimal to the right 8 places

8 0

3 years ago

Read 2 more answers

Y=1/6x + 5 what is the answer

kykrilka [37]

X should equal 6y-30

3 0

3 years ago

delia drove her car 179 miles. The car used 6.04 gallons of gasoline on the drive. Estimate the cars gasoline milage in miles pe

jok3333 [9.3K]

29.6 mpg is the answer.

8 0

3 years ago

Assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of

jarptica [38.1K]

Answer:

The "probability that a given score is less than negative 0.84" is $\\ P(z$ .

Step-by-step explanation:

From the question, we have:

The random variable is normally distributed according to a standard normal distribution, that is, a normal distribution with $\\ \mu = 0$ and $\\ \sigma = 1$ .
We are provided with a z-score of -0.84 or $\\ z = -0.84$ .

Preliminaries

A z-score is a standardized value, i.e., one that we can obtain using the next formula:

$\\ z = \frac{x - \mu}{\sigma}$ [1]

Where

x is the raw value coming from a normal distribution that we want to standardize.
And we already know that $\\ \mu$ and $\\ \sigma$ are the mean and the standard deviation, respectively, of the normal distribution.

A z-score represents the distance from $\\ \mu$ in standard deviations units. When the value for z is negative, it "tells us" that the raw score is below $\\ \mu$ . Conversely, when the z-score is positive, the standardized raw score, x, is above the mean, $\\ \mu$ .

Solving the question

We already know that $\\ z = -0.84$ or that the standardized value for a raw score, x, is below $\\ \mu$ in 0.84 standard deviations.

The values for probabilities of the standard normal distribution are tabulated in the standard normal table, which is available in Statistics books or on the Internet and is generally in cumulative probabilities from negative infinity, - $\\ \infty$ , to the z-score of interest.

Well, to solve the question, we need to consult the standard normal table for $\\ z = -0.84$ . For this:

Find the cumulative standard normal table.
In the first column of the table, use -0.8 as an entry.
Then, using the first row of the table, find -0.04 (which determines the second decimal place for the z-score.)
The intersection of these two numbers "gives us" the cumulative probability for z or $\\ P(z$ .

Therefore, we obtain $\\ P(z$ for this z-score, or a slightly more than 20% (20.045%) for the "probability that a given score is less than negative 0.84".

This represent the area under the standard normal distribution, $\\ N(0,1)$ , at the left of z = -0.84.

To "draw a sketch of the region", we need to draw a normal distribution (symmetrical bell-shaped distribution), with mean that equals 0 at the middle of the distribution, $\\ \mu = 0$ , and a standard deviation that equals 1, $\\ \sigma = 1$ .

Then, divide the abscissas axis (horizontal axis) into equal parts of one standard deviation from the mean to the left (negative z-scores), and from the mean to the right (positive z-scores).

Find the place where z = -0.84 (i.e, below the mean and near to negative one standard deviation, $\\ -\sigma$ , from it). All the area to the left of this value must be shaded because it represents $\\ P(z$ and that is it.

The below graph shows the shaded area (in blue) for $\\ P(z$ for $\\ N(0,1)$ .

7 0

3 years ago