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zalisa [80]
3 years ago
9

the track team is trying to reduce their time for a relay race. First they reduce their time by 2.1 minutes. then they are able

to reduce their time by 1/10. If their final time is 3.96 minutes what was their beginning time?
Mathematics
1 answer:
iVinArrow [24]3 years ago
8 0

Answer:

The beginning time of relay race is 6.73 minutes

Step-by-step explanation:

Given as :

The final time of relay race = 3.96 minutes

Let The initial time of relay race = x minutes

At first, The time reduce by 2.1 min

So, The first time become = ( x - 2.1 ) min

At second , The time reduce by \dfrac{1}{10} = 0.1

So, The time become =  ( x - 2.1 ) min - \dfrac{x}{10} min

\dfrac{10 (x - 2.1) - x}{10}

Or,  \dfrac{9 x - 21}{10}

∵ final time of race = 3.96 min

∴ \dfrac{9 x - 21}{10} = 3.96

Or, 9 x - 21 = 3.96 × 10

Or, 9 x = 39.6 + 21

Or, 9 x = 60.6

∴  x = \dfrac{60.6}{9}

i.e  x = 6.73 minutes

So, The beginning time = x = 6.73 min

Hence,The beginning time of relay race is 6.73 minutes Answer

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Answer:

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Step-by-step explanation:

Previous concepts

A hypothesis is defined as "a speculation or theory based on insufficient evidence that lends itself to further testing and experimentation. With further testing, a hypothesis can usually be proven true or false".  

The null hypothesis is defined as "a hypothesis that says there is no statistical significance between the two variables in the hypothesis. It is the hypothesis that the researcher is trying to disprove".  

The alternative hypothesis is "just the inverse, or opposite, of the null hypothesis. It is the hypothesis that researcher is trying to prove".  

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Type II error, also known as a "false negative" is the error of not rejecting a null  hypothesis when the alternative hypothesis is the true. Can be interpreted as the error of failing to accept an alternative hypothesis when we don't have enough statistical power.  

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On this case we want to test if the proportion of children diagnosed with Autism Spectrum Disorder (ASD) is different from 0.0147, so the system of hypothesis would be:

Null hypothesis: p= 0.0147

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