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3 years ago

25 points for grabs!

Mathematics

1 answer:

coldgirl [10]3 years ago

3 0

Answer:

6 marbles

Step-by-step explanation:

Let the initial number of marbles be x

Then added 3 and got 9 as final number

<u>Equation for this and solution</u>

x + 3 = 9
x = 9 - 3
x = 6

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Simplify 2^4×2^3/2^5×2^4 leaving your answer in index form

denis23 [38]

Step-by-step explanation:

$\frac{2^4 * 2^3}{2^5 * 2^4}$
$\frac{2^(4+3)}{2^(5+4)}$
$\frac{2^7}{2^9}$
2^(7-9)
2^(-2)

3 0

3 years ago

Read 2 more answers

jayden and carson are selling t-shirts and sweatshirts for a fundraiser. jayden sells 9 t-shirts and 3 sweatshirts for $288. car

Genrish500 [490]

Answer:

sweatshirts cost $42

t-shirts cost $18

Step-by-step explanation:

9x+3y=288

x+6y=270

substitute 270-6y for x in the first problem

9(270-6y) +3y=288

2430-54y+3y=288

2430-51y=288

51y=-2142

y=42

then plug y=42 into the second equation

x+6(42)=270

x+252=270

x=18

3 0

3 years ago

Chelsea buys 8 packs of markers. Each pack contains the same number of markers. Chelsea gives 10 markers to her brother. Then, s

amm1812

I think 36 markers in each pack

7 0

3 years ago

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Calculate the distance between the points -11 and 4 on a number<br> line.

krek1111 [17]

Answer:

15, d

Step-by-step explanation:

The absolute value of |-11| + |4| is 11+4 which is 15

5 0

3 years ago

A chemist examines 12 sedimentary samples for bromide concentraction. The mean bromide concentration for the sample date is 0.43

Umnica [9.8K]

Answer:

a) $z = 1.645$

b) Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

Step-by-step explanation:

Population is approximately normal, so we can find the normal confidence interval.

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$ . This is the critical value, the answer for a).

Now, find M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.645*\frac{0.0325}{\sqrt{12}} = 0.015$

The lower end of the interval is the sample mean subtracted by M. So it is 0.437 - 0.015 = 0.422cc/m³.

The upper end of the interval is the sample mean added to M. So it is 0.437 + 0.015 = 0.452 cc/m³.

Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

4 0

3 years ago