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pshichka [43]
3 years ago
11

If a boat goes down stream 72 milesind upstream 60 miles in 6 hours, the rate of the river and the rate of the boat in still wat

er respectively are
Mathematics
1 answer:
andre [41]3 years ago
3 0

Answer:

Speed of boat in still water = 11 miles per hour.

Step-by-step explanation:

Speed = distance / time

or

Distance= Speed * time

Let s be speed of the boat upstream and r be the speed of the river.

Then

Upstream speed=  s- r = 60/6= 10 miles per hour

Downstream speed= s+r= 72/6= 12 miles per hour

Therefore

s-r= 10--------- equation A

s+r= 12--------- equation B

Adding equation A and Eq. b

s-r= 10--------- equation A

<u>s+r= 12--------- equation B     </u>

<u>2s    = 22                             </u>

<u />

or

s= 22/2= 11 miles per hour.

Speed of boat in still water = 11 miles per hour.

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Paul [167]

Answer:

<h2><em><u>.1etc</u></em></h2>

Step-by-step explanation:

It would be 16 divided by 3 and from the answer you get from that you should divide it by itself equaling infinite .111111111111etc

4 0
3 years ago
Someone help me solve this and could you explain why too?
yulyashka [42]

Answer:

3.5

Step-by-step explanation:

Well its easiest to just plug in the answers and see like 2 times 3.5 is 7.

Another way is saying 7 divided by 2 is 3.5

then u check to make sure its the same for all the numbers.

Which it is because 21 divided by 6 is also 3.5 :)

5 0
3 years ago
Type the correct answer in each box. Use numerals instead of words. If necessary, use / for the fraction bar(s).
MAXImum [283]

Answer:

  • x = 15/p
  • x = -3

Step-by-step explanation:

<u>Given expression</u>

  • 4(px+1)=64

<u>Solving for x</u>

  • 4px + 4 = 64
  • 4px = 60
  • px = 15
  • x = 15/p

<u>Value of x when p= - 5</u>

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3 0
3 years ago
Read 2 more answers
Assume that the paired data came from a population that is normally distributed. using a 0.05 significance level and dequalsxmin
Artemon [7]
"<span>Assume that the paired data came from a population that is normally distributed. Using a 0.05 significance level and d = (x - y), find \bar{d}, s_{d}, the t-test statistic, and the critical values to test the claim that \mu_{d} = 0"

You did not attach the data, therefore I can give you the general explanation on how to find the values required and an example of a random paired data.

For the example, please refer to the attached picture.

A) Find </span><span>\bar{d}
You are asked to find the mean difference between the two variables, which is given by the formula:
\bar{d} =  \frac{\sum (x - y)}{n}

These are the steps to follow:
1) compute for each pair the difference d = (x - y)
2) sum all the differences
3) divide the sum by the number of pairs (n)

In our example: 
</span><span>\bar{d} =  \frac{6}{8} = 0.75</span>

B) Find <span>s_{d}
</span><span>You are asked to find the standard deviation, which is given by the formula:
</span>s_{d} =  \sqrt{ \frac{\sum(d - \bar{d}) }{n-1} }

These are the steps to follow:
1) Subtract the mean difference from each pair's difference 
2) square the differences found
3) sum the squares
4) divide by the degree of freedom DF = n - 1

In our example:
s_{d} = \sqrt{ \frac{101.5}{8-1} }
= √14.5
= 3.81

C) Find the t-test statistic.
You are asked to calculate the t-value for your statistics, which is given by the formula:
t =  \frac{(\bar{x} - \bar{y}) - \mu_{d} }{SE}

where SE = standard error is given by the formula:
SE =  \frac{ s_{d} }{ \sqrt{n} }

These are the steps to follow:
1) calculate the standard error (divide the standard deviation by the number of pairs)
2) calculate the mean value of x (sum all the values of x and then divide by the number of pairs)
3) calculate the mean value of y (sum all the values of y and then divide by the number of pairs)
4) subtract the mean y value from the mean x value
5) from this difference, subtract  \mu_{d}
6) divide by the standard error

In our example:
SE = 3.81 / √8
      = 1.346

The problem gives us <span>\mu_{d} = 0, therefore:
t = [(9.75 - 9) - 0] / 1.346</span>
  = 0.56

D) Find t_{\alpha / 2}
You are asked to find what is the t-value for a 0.05 significance level.

In order to do so, you need to look at a t-table distribution for DF = 7 and A = 0.05 (see second picture attached).

We find <span>t_{\alpha / 2} = 1.895</span>

Since our t-value is less than <span>t_{\alpha / 2}</span> we can reject our null hypothesis!!

7 0
3 years ago
2/4x1/2= what does it equal
nikklg [1K]

Answer:

0.25

Step-by-step explanation:

Hope this helps.

4 0
3 years ago
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