All categories

3 years ago

Suppose y varies directly with x. Write a direct variation equation that relates x and y. Then find the value of y when x = 7.

2 answers:

5 0

From the statement, y varies directly with x. It can be expressed as:

y α x

To change it to an equality, we insert a proportionality constant k.

y = kx

We first solve for k,

8 = k(-4)
k = -2

Therefore, when x = 7,

y = -2(7)
y = -14

Sonja [21]3 years ago

4 0

For direct variation, y = kx
8 = -4k
k = 8/-4 = -2

Therefore, required equation is y = -2x

when x = 7, y = -2(7) = -14

You might be interested in

Help. Ignore this i was told to write at least 20 characters

serg [7]

lol sommet i would do lol but i didnt ahaha

Answer:

follow steps below --------------------------------------(down arrow)

Step-by-step explanation:

to work out the surface area you would do

base times height

length times width

height times width then add all together

4 0

4 years ago

Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 99% confidenc

quester [9]

Answer: 18

Step-by-step explanation:

The formula to find the minimum sample size is given by :_

$n=(\dfrac{z^*\cdot \sigma}{E})^2$

, where $\sigma$ = population standard deviation.

z*= critical z-value.

E= Margin of error.

Given : $\sigma= 13$

E= ± 8

We know that critical value corresponding to 99% confidence level = z*=2.576 [Using z-table]

Then, the required sample size would be :

$n=(\dfrac{(2.576)\cdot (13)}{8})^2$

$\Rightarrow\ n=(4.186)^2$

$\Rightarrow\ n=17.522596\approx18$ [Round to next integer.]

Hence, the required minimum sample size = 18

4 0

4 years ago

Can someone help me? you might get a crown

Step2247 [10]

Answer:

2.1 mph

Step-by-step explanation:

7 0

3 years ago

Can you help answer this question

Darina [25.2K]

1:b
2:f
3:e
4:c
5:a
6:g
7:d
8:h

8 0

3 years ago

ASAP BRAINLIEST !! Luis is given the fraction 4/5. He is told to create an equivalent fraction with a numerator of 32. Explain t

solniwko [45]

Answer: answer 40.

Step-by-step explanation:

Note : lets make x the missing denominator.

I would take the 4/5 and set it equals to 32/x

we then cross multiply

where it would be 4 * x = 32 * 5

it would then be 4x = 160

we would then divide 160 by 4

x = 160/ 4

and x would be 40

.... therefore the missing denominator is 40.

8 0

3 years ago

Read 2 more answers