Does anyone know this question???

An office building has two elevators. One elevator starts out on the 4th floor, 35 feet above the ground, as it’s defending at a

iren2701 [21]

The system of equations are y = 35 - 2.2x and y = 1.7x

Solution:

Given that, office building has two elevators.

One elevator starts out on the 4th floor, 35 feet above the ground, as it’s descending at a rate of 2.2 feet per second

Let "x" be the number of seconds for which the elevator is descending

Therefore, for "x" seconds the descended feet is 2.2x feet

The elevator is at 4 th floor, 35 feet above ground

Therefore, from 35 feet, the elevator has descended 2.2x feet for "x" seconds

Let "y" be the final position of elevator after "x" seconds

Therefore,

y = 35 - 2.2x

The other elevator starts out at ground level and is rising at a rate of 1.7 feet per second

Here, the elevator is rising at a rate of 1.7 feet per second

Therefore, for "x" seconds, the elevator has raised 1.7x feet

Here the elevator is at ground level, therefore

y = 1.7x

Thus the system of equations are y = 35 - 2.2x and y = 1.7x

6 0

3 years ago

Need help. 7.58 × 10^2 convert with a standard and scientific notation

mixas84 [53]

The answer is 0.00758

7 0

3 years ago

Question 2 (Essay Worth 10 points)

Soloha48 [4]

Answer:

Account A: Decreasing at 8 % per year

Account B: Decreasing at 10.00 % per year

Account B shows the greater percentage change

Step-by-step explanation:

Part A: Percent change from exponential formula

f(x) = 9628(0.92)ˣ

The general formula for an exponential function is

y = ab^x, where

b = the base of the exponential function.

if b < 1, we have an exponential decay function.

ƒ(x) decreases as x increases.

Account A is decreasing each year.

We can rewrite the formula for an exponential decay function as:

y = a(1 – b)ˣ, where

1 – b = the decay factor

b = the percent change in decimal form

If we compare the two formulas, we find

0.92 = 1 - b

b = 1 - 0.92 = 0.08 = 8 %

The account is decreasing at an annual rate of 8 %.The account is decreasing at an annual rate of 10.00 %.

Account B recorded a greater percentage change in the amount of money over the previous year.

5 0

2 years ago

With a height of 68 in, Nelson was the shortest president of a particular club in the past century. The club presidents of the

Ivahew [28]

Answer:

a. The positive difference between Nelson's height and the population mean is: $\\ \lvert 68-70.7 \rvert = \lvert 70.7-68 \rvert\;in = 2.7\;in$ .

b. The difference found in part (a) is 1.174 standard deviations from the mean (without taking into account if the height is above or below the mean).

c. Nelson's z-score: $\\ z = -1.1739 \approx -1.174$ (Nelson's height is below the population's mean 1.174 standard deviations units).

d. Nelson's height is usual since $\\ -2 < -1.174 < 2$ .

Step-by-step explanation:

The key concept to answer this question is the z-score. A z-score "tells us" the distance from the population's mean of a raw score in standard deviation units. A positive value for a z-score indicates that the raw score is above the population mean, whereas a negative value tells us that the raw score is below the population mean. The formula to obtain this z-score is as follows:

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

Where

$\\ z$ is the z-score.

$\\ \mu$ is the population mean.

$\\ \sigma$ is the population standard deviation.

From the question, we have that:

Nelson's height is 68 in. In this case, the raw score is 68 in $\\ x = 68$ in.
$\\ \mu = 70.7$ in.
$\\ \sigma = 2.3$ in.

With all this information, we are ready to answer the next questions:

a. What is the positive difference between Nelson's height and the mean?

The positive difference between Nelson's height and the population mean is (taking the absolute value for this difference):

$\\ \lvert 68-70.7 \rvert = \lvert 70.7-68 \rvert\;in = 2.7\;in$ .

That is, the positive difference is 2.7 in.

b. How many standard deviations is that [the difference found in part (a)]?

To find how many standard deviations is that, we need to divide that difference by the population standard deviation. That is:

$\\ \frac{2.7\;in}{2.3\;in} \approx 1.1739 \approx 1.174$

In words, the difference found in part (a) is 1.174 standard deviations from the mean. Notice that we are not taking into account here if the raw score, x, is below or above the mean.

c. Convert Nelson's height to a z score.

Using formula [1], we have

$\\ z = \frac{x - \mu}{\sigma}$

$\\ z = \frac{68\;in - 70.7\;in}{2.3\;in}$

$\\ z = \frac{-2.7\;in}{2.3\;in}$

$\\ z = -1.1739 \approx -1.174$

This z-score "tells us" that Nelson's height is 1.174 standard deviations below the population mean (notice the negative symbol in the above result), i.e., Nelson's height is below the mean for heights in the club presidents of the past century 1.174 standard deviations units.

d. If we consider "usual" heights to be those that convert to z scores between minus2 and 2, is Nelson's height usual or unusual?

Carefully looking at Nelson's height, we notice that it is between those z-scores, because:

$\\ -2 < z_{Nelson} < 2$