What is12.869 x 5.847?.z

A lake has 10,000 fish.when a fishman scoops up his net ,he catches 500 fish. Suppose 150 of the 500 fish in his net are salmon.

Inessa [10]

You need x 20 to get to 10000, so do the same with 150 and get 3000, so it is 3000/10000

8 0

2 years ago

Read 2 more answers

Please help me I really need help

Oliga [24]

Answer:

Step-by-step explanation:

(1) 2x - 6y = -12

(2) x + 2y = 14

There is a -6y and a +2y. Since they have opposite signs, I'll try to eliminate the y terms. (That's my choice. There is more than one way to solve these.)

Multiply eq. (2) by 3:

3x + 6y = 42

Then add the result to eq. (1) to eliminate the y terms:

2x - 6y = -12

3x + 6y = 42

------------------

5x = 30, so x = 6

Now plug the value of x into eq. (2) and solve for y:

6 + 2y = 14

2y = 8

y = 4

Why did I use eq. (2) to solve for y? Because it's less work. I could have used eq. (1) instead:

2(6) - 6y = -12

12 - 6y = -12

-6y = -24

y = 4

More than one way to solve.

5 0

3 years ago

A study was conducted to measure the effectiveness of hypnotism in reducing pain. The measurements are centimeters on a pain sca

blondinia [14]

The confidence interval for mean of the "before-after" differences is $\fbox{(-0.4037,1.8037)}$

Further explanation:

Find the difference between the before pain and the after pain.

Difference = before-after

Kindly refer to the Table for the difference of between the before and after pain.

Sum of difference = $5.6$

Total number of observation = $8$

Mean of difference = $0.7$

Sample standard deviation $s$ = $1.3201$

Level of significance = $5\%$

Formula for confidence interval = $\left( \bar{X} \pm t_{n-1, \frac{\alpha}{2}\%} \frac{s}{\sqrt{n}} \right)$

confidence interval = $\left( 0.7 \pm t_{8-1, \frac{5}{2}\%} \frac{1.3201}{\sqrt{8}} \right)$

confidence interval = $\left( 0.7 \pm t_{7, \frac{5}{2}\%} \frac{1.3201}{\sqrt{8}} \right)$

From the t-table.

The value of $t_{7, \frac{5}{2}\%$ = $2.365$

Confidence interval = $( 0.7 \pm 2.365}\times \frac{1.3201}{\sqrt{8}}) \right)$

Confidence interval = $\left( 0.7 - 2.365}\times \0.4667,0.7 + 2.365}\times \0.4667) \right$

Confidence interval = $(0.7-1.1037,0.7+1.1037)$

Confidence interval = $\fbox{(-0.4037,1.8037)}$

The $95\%$ confidence interval tells us about that $95\%$ chances of the true mean or population mean lies in the interval.

Yes, the hypnotism appear to be effective in reducing pain as confidence interval include includes the positive deviation from the mean.

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Answer Details:

Grade: College Statistics

Subject: Mathematics

Chapter: Confidence Interval

Keywords:

Probability, Statistics, Speed dating, Females rating, Confidence interval, t-test, Level of significance , Normal distribution, Central Limit Theorem, t-table, Population mean, Sample mean, Standard deviation, Symmetric, Variance.