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3 years ago

18 take away negative 10 is wha

Mathematics

2 answers:

Elodia [21]3 years ago

5 0

The question 18-(-10)=28

Ilya [14]3 years ago

3 0

18--10=
the two negative signs make a plus so you simply have 18 + 10 which is 28

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Graphs that represent situations that may not have numerical values are Called?

vovikov84 [41]

Qualitative graphs.

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3 years ago

A pack of 9 toilet rolls costs £4.23

OleMash [197]

a) 9 toilet rolls cost $ 4.23
1 toilet roll costs $ x

9x = 4.23 * 1
x= 4.23 / 9
x = 0.47
So in first case one toilet roll costs $ 0.47.

b) 4 toilet rolls cost $1.96
1 toilet roll costs $ x

4x = 1.96 * 1
x = 1.96 / 4
x = 0.49
So in second case one toilet roll costs $ 0.49.

0.47 < 0.49
The toilet roll in first case is cheaper than the toilet roll in second case.

Hope this heps!

8 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

Kayla spent half of her weekly allowance on clothes. To earn more money her parents let her clean the oven for $4. What is her w

marysya [2.9K]

In this question, the first information that we get is that Kayla spent half of her weekly allowance in clothes. On cleaning the oven Kayla gets $4. Finally Kayla is left with $12.
Let us assume that the weekly allowance of Kayla = x
Amount of allowance saved after buying clothes = x/2
Then we can go for the equation
x/2 + 4 = 12
x + (4 * 2) = 12 * 2
x + 8 = 24
x = 24 -8
= 16
So we can now see that the weekly allowance of Kayla is $16

5 0

3 years ago

How much work must be done on a 1000-kg car to increase its speed from 1 m/s

yarga [219]

Answer:

w=f*d

f=ma

f=1000*10

f=10000

w=10000j

4 0

3 years ago