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2 years ago

6

Ming writes a number pattern on a slip of paper and hands it to his friend Jack. 24 21 23 20 22 19 21 18 Jack writes the next nu

mber in the pattern and hands the paper back to Ming. What number should Jack write?

1 answer:

tiny-mole [99]2 years ago

3 0

The rule is -3, then +2

24-3 = 21
21 + 2 = 23
23-3= 20
20+2= 22
22-3= 19
19+2 = 21
21-3= 18
18+2 = 20

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How to round 47,125 to the nearest ten,to the nearest hundred, to the nearest thousand and to the nearest ten thousand

Tasya [4]

To be able to round the number 47,125 to the nearest tenth, hundredth, and thousandth place you need to know were those places are. The tens place is the second one from the right hand side. The hundreds place is the third one from the right hand side and the thousands place is the one right after the comma. Now, to round to the tens place, you need to look at the place right behind it (which would be the ones place) then you need to analyze. If the number in the ones place is between 0-4 you can NOT round the tens place but, if it is between 5-9 you can. The same rule applies when you round to the hundreds and thousands place. So the number you should end up with is - 47,135.

8 0

2 years ago

Read 2 more answers

The cost function for a certain company is C = 20x + 700 and the revenue is given by R = 100x − 0.5x2. Recall that profit is rev

Brilliant_brown [7]

Answer:

x = 20

x = 140

Step-by-step explanation:

Find the equation for profit P

P = R - C

Substitute the equations for R and C then simplify.

P = 100x − 0.5x² - (20x + 700)

P = -0.5x² + 80x - 700

Find the values of x when profit is $700

P = -0.5x² + 80x - 700

700 = -0.5x² + 80x - 700

0 = -0.5x² + 80x - 1400

This is in the standard form 0 = ax² + bx + c

Use the quadratic formula to find values of x

$x = \frac{-b±\sqrt{b^{2}-4ac} }{2a}$

(Ignore Â)

Substitute a b and c.

a = -0.5

b = 80

c = -1400

$x = \frac{-(80)±\sqrt{80^{2}-4(-0.5)(-1400)} }{2(-0.5)}$

$x = \frac{-80±60}{-1}$

Split the formula at the ± so that there are two to get the two x values.

$x = \frac{-80+60}{-1}$

$x = \frac{-80-60}{-1}$

x = 20

x = 140

The profit will be $700 when x is 20 or when x is 140.

5 0

2 years ago

A rectangular storage container with an open top is to have a volume of 10m3. Thelength of its base is twice the width. Material

frutty [35]

Answer:

$163.54

Step-by-step explanation:

Volume of rectangular container = 10m^3

Length = 2(width)

Material for the base cost $10 per square meter

Material for the side cost $6 per square meter

Volume = L*B*H

L= 2W

V = (2W).W. H

10 = 2W^2.H

H = 10 /2W^2

H = 5/W^2

Let C(w) = cost function

C(w) = 10(L.W) + 6(2.L.H + 2.W.H)

= 10(2W.W) + 6(2.2W.H + 2.W.H)

= 10(2W^2) + 6(4W.H + 2.W.H)

= 10(2W^2) + 6(4W*5/W^2 + 2.W*5/W^2)

= 20W^2 + 6(20/W + 10/W)

= 20W^2 + 6((10+20)/W)

= 20W^2 + 6(30/W)

C(w) = 20W^2 + 180/W

To find the minimum value, differentiate C with respect to w

C'(w) = 40W - 180/W^2

Put C'(w) = 0

0 = 40W - 180/W^2

40W = 180/W^2

40W^3 = 180

W^3 = 180/40

W^3 = 4.5

W = cube rt(4.5)

W = 1.65m

C = 20(1.65)^2 + 180/1.65

C = 54.45 + 109.09

C= $163.54

Minimum cost = $163.54

6 0

2 years ago

A manufacturing company produces valves in various sizes and shapes. One particular valve plate is supposed to have a tensile st

maxonik [38]

Answer:

$z=\frac{5.0611-5}{\frac{0.2803}{\sqrt{42}}}=1.413$

$p_v =2*P(z>1.413)=0.158$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the average tensile strength is different from 5lbs/mm at 10% of signficance

Step-by-step explanation:

Data given and notation

$\bar X=5.0611$ represent the sample mean

$\sigma=0.2803$ represent the population standard deviation for the sample

$n=42$ sample size

$\mu_o =5$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is different from 5, the system of hypothesis would be:

Null hypothesis: $\mu = 5$

Alternative hypothesis: $\mu \neq 5$

If we analyze the size for the sample is > 30 but and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{5.0611-5}{\frac{0.2803}{\sqrt{42}}}=1.413$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z>1.413)=0.158$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the average tensile strength is different from 5lbs/mm at 10% of signficance

8 0

2 years ago

Consider the function represented by 9x + 3y= 12 with x as the independent variable. How can this function be written

Elena-2011 [213]

Answer: f(x) = -3x + 4

Step-by-step explanation:

The function is represented by

9x + 3y= 12

This is a linear equation with x as the independent variable. This means that if x is the independent variable, the y is the dependent variable. The values of y depends on the values of x. In order to represent the function, 9x + 3y= 12, we would rearrange the function such that y stands alone on the left hand side of the equation. This becomes

9x + 3y= 12

Subtracting 9x from both sides,

9x -9x + 3y = 12 - 9x

3y = 12-9x

Dividing the lefthand side and right hand side of the equation by 3, it becomes

3y/3 = (12-9x)/3

y= -3x + 4

using function notation,

y = f(x) = -3x + 4

8 0

2 years ago