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3 years ago

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HELPPP Paul is making two ceramic plates in his pottery class. One plate has a 20-centimeter diameter and a 62.8-centimeter circ

umference. A smaller plate has a radius of 5 centimeters. What is its circumference?

1 answer:

nikitadnepr [17]3 years ago

5 0

Answer:

It’s 2+2=x 3x3=18 that’s the answer

Step-by-step explanation:

You might be interested in

Show that the sum of two concave functions is concave. Is the product of two concave functions also concave?

spayn [35]

Answer with explanation:

Let us assume that the 2 functions are:

1) f(x)

2) g(x)

Now by definition of concave function we have the first derivative of the function should be strictly decreasing thus for the above 2 function we conclude that

$\frac{d}{dx}\cdot f(x)$

Now the sum of the 2 functions is shown below

$y=f(x)+g(x)$

Diffrentiating both sides with respect to 'x' we get

$\frac{dy}{dx}=\frac{d}{dx}\cdot f(x)+\frac{d}{dx}\cdot g(x)\\\\$

Since each term in the right of the above equation is negative thus we conclude that their sum is also negative thus

$\frac{dy}{dx}$

Thus the sum of the 2 functions is also a concave function.

Part 2)

The product of the 2 functions is shown below

$h=f(x)\cdot g(x)$

Diffrentiating both sides with respect to 'x' we get

$h'=\frac{d}{dx}\cdot (f(x)\cdot g(x))\\\\h'=g(x)f'(x)+f(x)g'(x)$

Now we can see the sign of the terms on the right hand side depend on the signs of the function's themselves hence we remain inconclusive about the sign of the product as a whole. Thus the product can be concave or convex.

8 0

3 years ago

Suppose you are interested in the effect of skipping lectures (in days missed) on college grades. You also have ACT scores and h

DIA [1.3K]

Answer:

a) For this case the intercept of 2.52 represent a common effect of measure for any student without taking in count the other variables analyzed, and we know that if HSGPA=0, ACT= 0 and skip =0 we got $colGPA=2.52$

b) This value represent the effect into the ACT scores in the GPA, we know that:

$\hat \beta_{ACT} = 0.015$

So then for every unit increase in the ACT score we expect and increase of 0.015 in the GPA or the predicted variable

c) If we are interested in analyze if we have a significant relationship between the dependent and the independent variable we can use the following system of hypothesis:

Null Hypothesis: $\beta_i = 0$

Alternative hypothesis: $\beta_i \neq 0$

Or in other wouds we want to check if an specific slope is significant.

The significance level assumed for this case is $\alpha=0.05$

Th degrees of freedom for a linear regression is given by $df=n-p-1 = 45-3-1 = 41$ , where p =3 the number of variables used to estimate the dependent variable.

In order to test the hypothesis the statistic is given by:

$t=\frac{\hat \beta_i}{SE_{\beta_i}}$

And replacing we got:

$t = \frac{-0.5}{0.0001}=-5000$

And for this case we see that if we find the p value for this case we will get a value very near to 0, so then we can conclude that this coefficient would be significant for the regression model .

Step-by-step explanation:

For this case we have the following multiple regression model calculated:

colGPA =2.52+0.38*HSGPA+0.015*ACT-0.5*skip

Part a

(a) Interpret the intercept in this model.

For this case the intercept of 2.52 represent a common effect of measure for any student without taking in count the other variables analyzed, and we know that if HSGPA=0, ACT= 0 and skip =0 we got $colGPA=2.52$

(b) Interpret $\hat \beta_{ACT}$ from this model.

This value represent the effect into the ACT scores in the GPA, we know that:

$\hat \beta_{ACT} = 0.015$

So then for every unit increase in the ACT score we expect and increase of 0.015 in the GPA or the predicted variable

(c) What is the predicted college GPA for someone who scored a 25 on the ACT, had a 3.2 high school GPA and missed 4 lectures. Show your work.

For this case we can use the regression model and we got:

$colGPA =2.52 +0.38*3.2 +0.015*25 - 0.5*4 = 26.751$

(d) Is the estimate of skipping class statistically significant? How do you know? Is the estimate of skipping class economically significant? How do you know? (Hint: Suppose there are 45 lectures in a typical semester long class).

If we are interested in analyze if we have a significant relationship between the dependent and the independent variable we can use the following system of hypothesis:

Null Hypothesis: $\beta_i = 0$

Alternative hypothesis: $\beta_i \neq 0$

Or in other wouds we want to check if an specific slope is significant.

The significance level assumed for this case is $\alpha=0.05$

Th degrees of freedom for a linear regression is given by $df=n-p-1 = 45-3-1 = 41$ , where p =3 the number of variables used to estimate the dependent variable.

In order to test the hypothesis the statistic is given by:

$t=\frac{\hat \beta_i}{SE_{\beta_i}}$

And replacing we got:

$t = \frac{-0.5}{0.0001}=-5000$

And for this case we see that if we find the p value for this case we will get a value very near to 0, so then we can conclude that this coefficient would be significant for the regression model .

7 0

3 years ago

URGENT ANSWER NOW In △ABC, A=59∘, a=20, and c=21. What are the two possible values for angle C to the nearest tenth of a degree?

PilotLPTM [1.2K]

Answer:

The two possible values of C are 64.2° and 115.8°

Step-by-step explanation:

* In ΔABC

- a, b, c are the lengths of its 3 sides, where

# a is opposite to angle A

# b is opposite to angle B

# c is opposite to angle C

- m∠A = 59°

- a = 20

- c = 21

* To find the distance m∠C we can use the sin Rule

- In any triangle the ratio between the length of each side

to the measure of each opposite angle are equal

- c/sinC = a/sinA = b/sinB

* Lets use it to find the m∠C

∵ 21/sinC = 20/sin(59)

∴ sin(C) = 21 × sin(59) ÷ 20 = 0.9000256657

∴ m∠C = sin^-1(0.9000256657) = 64.16144°

∴ m∠C = 64.2°

∵ The value of sin(C) is positive

∴ Angle C may be in the first quadrant (acute angle)

or in the second quadrant (obtuse angle)

∴ The other measure of ∠C = 180 - 64.2 = 115.8

* The two possible values of C are 64.2° and 115.8°

6 0

3 years ago

Point Lis a centroid of the triangle FWD, If RL = 54 cm, what is RD?

Wittaler [7]

Answer:

RD = 162 cm

Step-by-step explanation:

LD = 2 RL = 2* 54 = 108

RD = RL + LD

RD = 54 + 108

RD = 162 cm

7 0

3 years ago

-14,-10,_,-2,2,6 missing sequence

OLga [1]

-14,-10,-6,-2,2,6

Answer by Mimiwhatsup: I could easily subtract -14 from -10 to find out the sequence so they are adding four each time. That means the pattern will continue going on like this 10, 14, 18, 22 and so forth.

6 0

3 years ago