3pt b) Suggest one way that is always under the control of the researcher of making the margin of error smaller.

Answer:

c=80

Step-by-step explanation:

Based on my reading the critical damping occurs when the discriminant of the quadratic characteristic equation is 0.

So let's see that characteristic equation:

20⁢r^2+c⁢r+80⁢=0

The discriminant can be found by calculating b^2-4aC of ar^2+br+C=0.

a=20

b=c

C=80

c^2-4(20)(80)

We want this to be 0.

c^2-4(20)(80)=0

Simplify:

c^2-6400=0

Add 6400 on both sides:

c^2=6400

Take square root of both sides:

c=80 or c=-80

Based on further reading damping equations in form

a⁢y′⁢′+b⁢y′+C⁢y=0

should have positive coefficients with b also having the possibility of being zero.

Answer:

0.6524 = 65.24% probability that the runner will average between 146 and 150 minutes in these 49 marathons.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Average of 147 minutes with a standard deviation of 12 minutes.

This means that [tex]\mu = 147, \sigma = 12[/tex]

Consider 49 of the races.

This means that [tex]n = 49, s = \frac{12}{\sqrt{49}} = \frac{12}{7} = 1.7143[/tex]

Find the probability that the runner will average between 146 and 150 minutes in these 49 marathons.

This is the p-value of Z when X = 150 subtracted by the p-value of Z when X = 146. So

X = 150

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{150 - 147}{1.7143}[/tex]

[tex]Z = 1.75[/tex]

[tex]Z = 1.75[/tex] has a p-value of 0.9599

X = 146

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{146 - 147}{1.7143}[/tex]

[tex]Z = -0.583[/tex]

[tex]Z = -0.583[/tex] has a p-value of 0.3075.

0.9599 - 0.3075 = 0.6524.

0.6524 = 65.24% probability that the runner will average between 146 and 150 minutes in these 49 marathons.

Answer:

12/55

Step-by-step explanation:

Probability is the ratio of the number of possible outcomes to the number of total outcomes.

Given that the bag contains 8 red balls and 3 white balls, the probability of picking a red ball

p(r) = 8/(8+3) = 8/11

Probability of picking a white ball

= 3/11

when a red ball is picked first, the total number of balls reduces to 10 hence the probability that the second ball is white, given that the first ball is red

=8/11 * 3/10

= 24/110

= 12/55

Answer:

Hello,

5 s

Step-by-step explanation:

[tex]h(t)=-16t^2+48t+160\\=-16(t^2-3t-10)\\=-16(t^2-5t+2t-10)\\=-16(t(t-5)+2(t-5))\\=-16(t-5)(t+2)\\\\h(t)=0 \Longleftrightarrow\ t=-2\ or\ t=5\\\\Only\ t=5\ is \ a\ answer.(time\ must\ be\ positive)[/tex]

The 3rd one

Step-by-step explanation:

Reason being that it has no factors, meaning it cannot be simplified any further, but quadratic method can be used to attain factors.

hope it makes sense :)

Answer:

All of area is πr²

Step-by-step explanation:

and we should write the area kind of radian. So if all area is π*(12)²= 144π - this for 360°- and 240° is 96π

but we must add area of the triangle which has two same side and has 6 high so it's area is 6*12√3/2 = 36✓3

our answer is 96π+ 36✓3

Answer:

125000000

Step-by-step explanation:

1.25 x 10^8

Move the decimal 8 places to the right

1.25

We can move it two places

125

We need to add 6 more zeros

125000000

Answer: 125,000,000

Step-by-step explanation:

Answer:

1 + 7n

Step-by-step explanation:

7-(3n+6)+10n​

7 - 3n - 6 + 10 n

1 - 7n

Answered by Gauthmath

Answer:

Whole number —> X

Twice the square of the number —> 2X²

X + 2X² = 10

2X²+X –10 =0

(2x + 5) ( x–2) =0

2x +5=0 —> 2x= – 5 —> x= – 5/2 = —> x= - 2.5 (rejected)

x–2=0 —> x= 2

So Ans ; X= 2 ( the number )

I hope I helped you^_^

Answer:

slope= 3/1

y-intercept (0,2)

y= 3/1 b + 2

Answer:

The answer is A

Step-by-step explanation:

The answer needs to be in slope-intercept form or y=mx+b because the amount of carpet being cleaned every minute is a constant decrease of 9 square feet.

So our b value (or how much carpet cleaned at 0 minutes) is 220

And our m value (or slope or how much carpet is being cleaned every minute) is 9

So if we plug the variables with the tangible numbers we get A(t) = -9x+220 or A(t) = 220-9x.

provided by gauth math

Answer:

x=1.7099

Step-by-step explanation:

2x³=10

x³=10/2

x³=5

x=∛5

x=1.7099

9514 1404 393

Answer:

Step-by-step explanation:

Reflection over the x-axis changes the sign of the y-coordinate. Reflection over the y-axis changes the sign of the x-coordinate. We can summarize the transformations as ...

  preimage point ⇒ reflection over x ⇒ reflection over y

A(−8,−2) ⇒ A'(-8, 2) ⇒ A"(8, 2)

B(−4,−3) ⇒ B'(-4, 3) ⇒ B"(4, 3)

C(−2,−8) ⇒ C'(-2, 8) ⇒ C"(2, 8)

D(−10,−6) ⇒ D'(-10, 6) ⇒ D"(10, 6)

Answer:

See pic below.

Answer: C. 380°

Step-by-step explanation:

9514 1404 393

Answer:

Step-by-step explanation:

If n represents the number, we have ...

  10(-270 +n) = -20 . . . an equation for n

__

The solution can be found as ...

  -270 +n = -2 . . . . . divide by 10

  n = 268 . . . . . . . add 270

The number is 268.

Answer:

base-2 base-10

110011 = 51

110100 = 52

110101 = 53

110110 = 54

21 more rows

Answer:

The situation that represents this situation is:

[tex]t = \frac{60}{n}[/tex]

Step-by-step explanation:

The amount of time t needed to assemble the set is inversely  proportional to the number people n working.

This means that:

[tex]t = \frac{k}{n}[/tex]

In which k is the constant of proportionality.

Twelve people can assemble the set in 5 hours.

This means that for [tex]n = 12, t = 5[/tex]. We use this to find k.

[tex]t = \frac{k}{n}[/tex]

[tex]5 = \frac{k}{12}[/tex]

[tex]k = 12*5 = 60[/tex]

Write an equation to represent the situation.

[tex]t = \frac{60}{n}[/tex]

GIVEN -> Triangles r similar

so sides r in ratio

[tex] \frac{2.4}{3} = \frac{2.8}{x} \\ 0.8 = \frac{2.8}{x} \\ x = \frac{2.8}{0.8} \\ x = \frac{28}{8} \\ x = 3.5 \: \: ans[/tex]

Answer:

3.5

Step-by-step explanation:

We can write a ratio to solve

2.4      2.8

----- = --------

3         x

Using cross products

2.4x = 3(2.8)

2.4x =8.4

Divide each side by 2.4

2.4x /2.4 = 8.4/2.4

x = 3.5

Answer:

10610

Step-by-step explanation:

Given,

T=6years

R=3.2%

A=86125

Now,

CA=P[1+R/10]^T

or,P=86125/[1+3.2/10]^6

=86125/5.29

=10610

Answer:

Each chocolate truffle is $2.125

Step-by-step explanation:

Honestly, I'm not 100% sure if this is correct, and I am truly sorry if this is wrong, but its worth a try :)

Answer:

see below

Step-by-step explanation:

Part A

The slope is found by

m = ( y2-y1)/(x2-x1)

    = ( 1200-1500)/(4-0)

    = -300/4

    =-75

Part B

point slope  y-y1 = m(x-x1)  where m is the slope and (x1,y1) is a point on the line

y-1200 = -75(x-4)

slope intercept  y = mx+b  where m is the slope and b is the y intercept

y = -75x + 1500

standard form  Ax+By =C

75x + y = 1500

Part C

Change y to g(x) in the slope intercept form

g(x) = -75x + 1500

Part D

Let x = 5

g(5) = -75(5) + 1500

      =-375+1500

      =1125

Answer: 0.38

Step-by-step explanation:

Since the variable x is represented by a standard normal distribution, the probability of x > 0.3 will be calculated thus:

P(x > 0.3)

Then, we will use a standard normal table

P(z > 0.3)

= 1 - p(z < 0.3)

= 1 - 0.62

= 0.38

Therefore, p(x > 0.3) = 0.38

The probability of x > 0.3 is 0.38.

[tex]\sf\huge\underline\color{pink}{༄Answer:}[/tex]

[tex]\tt3 \frac{1}{3} = \frac{x}{6} \\ = \tt \frac{10}{3} = \frac{x}{6} \\ = \tt \frac{x}{6} = \frac{10}{3} \\ = \tt6 \frac{x}{6} = 6( \frac{10}{3} ) \\ = \tt\large\boxed{\tt{\color{pink}{x = 20}}}[/tex]

[tex]\color{pink}{==========================}[/tex]

#CarryOnLearning

Answer:

Step-by-step explanation:

1 dollar = 30 cents tax + 70 cents net income

The ratio of taxes to net income:

Correct choice is D

If 30cents are out then net income=100-30=70

ratio:-

[tex]\\ \rm\Rrightarrow \dfrac{30}{70}[/tex]

[tex]\\ \rm\Rrightarrow \dfrac{3}{7}[/tex]

[tex]\\ \rm\Rrightarrow 3:7[/tex]

Step-by-step explanation:

7 times a certain number :

Let the unknown number be x

[tex]7 \times x[/tex]

is less four times that same number -2 is 58 :

7x - 4x -2 = 58

Collect like terms

7x-4x = 58+2

3x = 60

3x/3 = 60/3

x = 20

Let the number be x

ATQ

[tex]\\ \sf\longmapsto 7x-4x-2=58[/tex]

[tex]\\ \sf\longmapsto 3x-2=58[/tex]

[tex]\\ \sf\longmapsto 3x=58+2[/tex]

[tex]\\ \sf\longmapsto 3x=60[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{60}{3}[/tex]

[tex]\\ \sf\longmapsto x=20[/tex]