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borishaifa [10]

3 years ago

13

The sum of three numbers is 90. The third number is 10 less than the first. The second number is 3 times the third. What are the

numbers?

1 answer:

Katyanochek1 [597]3 years ago

6 0

Answer:

16

26

48

Step-by-step explanation:

x + y + z = 90

z = x - 10 => x = z + 10

y = 3z

=>

(z+10) + 3z + z = 90

5z + 10 = 90

5z = 80

z = 16

x = z + 10 = 16 + 10 = 26

y = 3z = 3×16 = 48

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In an area of the Midwest, records were kept on the relationship between the rainfall (in inches) and the yield of wheat (bushel

dusya [7]

Answer:

The correct answer is 36.2

Step-by-step explanation:

Hello!

Given the data:

Rainfall(inch) x: 10.5, 8.8, 13.4, 12.5, 18.8, 10.3, 7.0, 15.6, 16.0

Yield (bushels per acre) y: 50.5, 46.2, 58.8, 59.0, 82.4, 49.2, 31.9, 76.0, 78.8

The response variable is

Y: Yield of wheat (bushels per acre)

Explanatory variable:

X: Rainfall in a certain period (inch)

I've calculated the equation of regression using a statistics software, the estimated equation is:

^Y= 4.27 + 4.38X

To calculate the value that will take the response variable for a given value of X:

^Y= 4.27 + 4.38*7.3= 36.24 bushels per acre.

I hope it helps!

5 0

3 years ago

Read this E[2X^2 â€" Y].

djyliett [7]

Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.

If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:

E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]

Or, if you're given the expectation and variance of <em>X</em>, you have

Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²

→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]

Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.

6 0

3 years ago

If a cantaloupe weighs 2 3/8 pounds, a watermelon weighs 6.25 pounds, and a honeydew melon weighs 3 1/2 pounds, what is the tota

Mariana [72]

the answer to this question would be 12 and 1/8

3 0

3 years ago

One sign lights up every 10 seconds. One sign lights up every 12 seconds. If they have just lit up at the same time, how many se

andrew11 [14]

Answer:

It will take 60 seconds for the signs to light up at the same time again.

Step-by-step explanation:

Given:

One sign lights up every 10 seconds

One sign lights up every 12 seconds

They have just lit up at the same time.

To find in how many seconds will it take for the signs to light up at the same time again.

Solution:

In order to find the time in seconds will it take for the signs to light up at the same time again, we need to find the least common multiple of the the times for which the given signs light up.

The numbers are 10 and 12.

To find the LCM, we will list the multiples of each and check the least common multiple.

The multiples of 10 and 12 are :

$10\rightarrow 10,20,30,40,50,60,70$

$12\rightarrow 12,24,36,48,60$

thus, we can see that 60 is the least common multiple.

Thus, the signs will light up at the same time time after every 60 seconds.

7 0

3 years ago

Solve for the value of x: 3x + 25 = 2/3 (6x - 15)

n200080 [17]

3x + 25 = 2/3 (6x - 15)

9x + 75 = 12x - 30

75 + 30 = 12x - 9x

3x = 105

x = 105 : 3

x = 35

3 0

3 years ago