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2 years ago

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Andrea and her partner and writing a 12-page science report. They completed 25% of the report in class and 50% of the remaining

pages after school. how many pages do Andrea and her partner still have to write?
possible answers are 3.5, 4.5, 6, and 9.

1 answer:

Alex_Xolod [135]2 years ago

5 0

It can't be six because half of twelve is six and you've completed %75 so its 4.5

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Please help me out I will name the brainliest!!!!<br> Answer question 1-8!

klio [65]

Answer:

Step-by-step explanation:

3. function

4. not a function

5. function

6. not a function

7. function

8. not a function

8 0

2 years ago

-1/6 + 2/3 ( 9 + - 3/4) + - 1/2

Liono4ka [1.6K]

First simplify the section in the parenthesis.
-1/6 + 2/3(8 1/4) + -1/2
Then multiply 2/3 by 8 1/4.
-1/6 + 5 1/2 + -1/2
Add -1/2 to 5 1/2.
-1/6 + 5
Add 5 to -1/6.
4 5/6 is the fully simplified answer.
Hope this helps!

7 0

2 years ago

Solve the following system of equations for a and for b:

viktelen [127]

Answer:

$a=3\\b=1$

Step-by-step explanation:

$9a+3b=30\\8a+4b=28$

Let's solve the second equation for a to later on replace it in the first equation.

$8a+4b=28\\8a=28-4b\\a=\frac{28-4b}{8}$

Now plug this into the first equation.

$9a+3b=30\\9(\frac{28-4b}{8})+3b=30$

Distribute the 9

$(\frac{252-36b}{8}) +3b=30$

Break down the fraction.

$\frac{252}{8}-\frac{36b}{8}+3b=30$

Simplify.

$\frac{63}{2}-\frac{9}{2}b+3b=30$

Subtract $\frac{63}{2}$

$-\frac{9}{2}b+3b=30-\frac{63}{2}$

Combine like terms.

$\frac{-9+2*3}{2}b=\frac{30*2-63}{2}$

$\frac{-9+6}{2}b=\frac{60-63}{2}$

$\frac{-3}{2}b=\frac{-3}{2}$

Muliply by the reciprocal or inverted fraction next to b.

$(-\frac{2}{3})(-\frac{3}{2}) b=-\frac{3}{2}(-\frac{2}{3})$

$b=1$

Now plug this value into any of the equations to find the value of a.

$8a+4b=28\\8a+4(1)=28\\8a+4=28\\8a=28-4\\8a=24\\a=\frac{24}{8}\\ a=3$

5 0

3 years ago

What is the value of 9p5?

ICE Princess25 [194]

9.5 is correct (:(:(:

6 0

2 years ago

In a sample of eight whitefish caught in Yellowknife Bay, the mean arsenic concentration in the liver was 0.32 mg/kg, with a sta

Advocard [28]

Answer:

The 95% confidence interval for the concentration in whitefish found in Yellowknife Bay is (0.2698 mg/kg, 0.3702 mg/kg).

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 8 - 1 = 7

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 7 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.95}{2} = 0.975$ . So we have T = 2.3246

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.3646\frac{0.06}{\sqrt{8}} = 0.0502$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 0.32 - 0.0502 = 0.2698 mg/kg

The upper end of the interval is the sample mean added to M. So it is 0.32 + 0.0502 = 0.3702 mg/kg

The 95% confidence interval for the concentration in whitefish found in Yellowknife Bay is (0.2698 mg/kg, 0.3702 mg/kg).

8 0

2 years ago