All categories

3 years ago

HELP

Mathematics

1 answer:

I am Lyosha [343]3 years ago

5 0

Step-by-step explanation:

since Chelsea can paint in 9hrs and Greg in 7, add the hrs and divide by 2 i.e (9+7)/2 =8 hrs

~10 hrs

MARK AS BRAINLIEST PLEASE

You might be interested in

What is the formula of CP

agasfer [191]

Answer:

CP= SP*100\100+profit percent

CP=SP*100/100-loss percent

Step-by-step explanation:

i hope you have understood

4 0

3 years ago

A laboratory scale is known to have a standard deviation (sigma) or 0.001 g in repeated weighings. Scale readings in repeated we

weqwewe [10]

Answer:

99% confidence interval for the given specimen is [3.4125 , 3.4155].

Step-by-step explanation:

We are given that a laboratory scale is known to have a standard deviation (sigma) or 0.001 g in repeated weighing. Scale readings in repeated weighing are Normally distributed with mean equal to the true weight of the specimen.

Three weighing of a specimen on this scale give 3.412, 3.416, and 3.414 g.

Firstly, the pivotal quantity for 99% confidence interval for the true mean specimen is given by;

P.Q. = $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean weighing of specimen = $\frac{3.412+3.416+3.414}{3}$ = 3.414 g

$\sigma$ = population standard deviation = 0.001 g

n = sample of specimen = 3

$\mu$ = population mean

<em>Here for constructing 99% confidence interval we have used z statistics because we know about population standard deviation (sigma).</em>

So, 99% confidence interval for the population mean, $\mu$ is ;

P(-2.5758 < N(0,1) < 2.5758) = 0.99 {As the critical value of z at 0.5% level

of significance are -2.5758 & 2.5758}

P(-2.5758 < $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ < 2.5758) = 0.99

P( $-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X - \mu}$ < $2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

P( $\bar X-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

<u>99% confidence interval for</u> $\mu$ = [ $\bar X-2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+2.5758 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $3.414-2.5758 \times {\frac{0.001}{\sqrt{3} } }$ , $3.414+2.5758 \times {\frac{0.001}{\sqrt{3} } }$ ]

= [3.4125 , 3.4155]

Therefore, 99% confidence interval for this specimen is [3.4125 , 3.4155].

6 0

3 years ago

<img src="https://tex.z-dn.net/?f=5x-4%2B2%28x-4%29%3D16" id="TexFormula1" title="5x-4+2(x-4)=16" alt="5x-4+2(x-4)=16" align="ab

mariarad [96]

Answer:

$\boxed{x = 4}$

Step-by-step explanation:

=> 5x-4+2(x-4) = 16

Expanding the brackets

=> 5x-4+2x-8 = 16

Combining like terms

=> 5x+2x-4-8 = 16

=> 7x - 12 = 16

Adding 12 to both sides

=> 7x = 16+12

=> 7x = 28

Dividing both sides by 7

=> x = 4

3 0

3 years ago

Read 2 more answers

MANY POINTS! PLEASE HELP

Vlad1618 [11]

Answer:

B. 51.7699^2

Step-by-step explanation:

Last 2 wrong because it is positive.

101.... is not the definite integral for the curve

51... purrfecto

3 0

2 years ago

Three vertices of a rectangle are (–2, 1), (–2, –3), and (4, –3)

Tpy6a [65]

The answer is C
it's easier if you graph it
we know that the x of the unknown vertice is 4, because this is a rectangle and that vertices has to be on the same x line as the point below.
y of the unknown vertice has to be 1 because the vertice to the left needs to be on the same y line as the unknown vertice

6 0

3 years ago