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kvv77 [185]
3 years ago
12

Two trains leave towns 474 kilometers apart at the same time and travel toward each other. One train travels13 km/m faster than

the other. If they meet in 2 hours, what is the rate of each train?
Mathematics
1 answer:
guajiro [1.7K]2 years ago
3 0

Answer:

112 km/h

125 km/hr

Step-by-step explanation:

Distance = time * speed

Distance  = distance train 1 + distance train 2

474 = 2(s) + 2(s + 13)

Distribute

474 = 2s + 2s + 26

Combine like terms

474 = 4s + 26

Subtract 26 from both sides

448 = 4s

Divide both sides by 4

112 = s

s = 112 km/h

s + 13 = 125 km/hr

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Answer:

- Sensitivity = 62.7 %

- specificity = 74.9 %

- positive predictive value = 45.2 %

- negative predictive value = 85.9 %

- Accuracy of the test = 71.9 %

Step-by-step explanation:

Given the data in th question;

                                 CONDITION POSITIVE    CONDITION NEGATIVE   TOTAL

TEST POSITIVE                   42                                       51                            93

TEST NEGATIVE                 25                                      152                          177

TOTAL                                  67                                     203                         270

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Sensitivity = [A / ( A + C) ]×100= [42 /( 42 + 25)]×100 = [42 / 67] 100=

Sensitivity = 62.7 %

specificity = [D / ( D + B) ]×100= [152 /( 152 + 51)]×100 = [152 / 203] 100=

specificity = 74.9 %

positive predictive value = [A / ( A + B) ]×100 = [42 /( 42 + 51)]×100 =[42/93] 100

positive predictive value = 45.2 %

negative predictive value =  [D / ( D + C) ]×100 = [152 /( 152 + 25)]×100 =[152/177] 100

negative predictive value = 85.9 %

Accuracy of the test = [A + D / ( A+B+C+D)] =  [42 + 152 / ( 42+51+25+152)]

= [ 194 / 270 ]

Accuracy of the test = 71.9 %

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3 years ago
I will give brainliest to the best answer to this question: Each year, the Department of Water Works measures the chloride conce
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Answer:

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Step-by-step explanation:

Given : The first year, they found the chloride concentration changed by -1\frac{3}{5} mg/L .

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