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Inessa05 [86]
2 years ago
8

Jeanie completed a 27 mile duathlon (a race that is a combination of running and biking) in exactly 2 hours. she ran an average

speed of 8.5 miles per hour and biked an average speed of 16 miles per hour. for how long did jeanie bike during the race?
Mathematics
1 answer:
-Dominant- [34]2 years ago
8 0
<span>Let x = the miles Jeanie ran y = the miles Jeanie biked T = 2 hours total time for the duathlon v1 = 8.5 mph Jeanie's running speed and v2 = 16 mph Jeanie's biking speed But T = Jean's time she ran t1 + time she biked t2 I. e t1 + t2 = 2 So we have average speed v2 when she biked = distance (y) / time (t2) Distance y = v2 * t2 = 16 * t2 and distance when she ran x = 8.5 * t1 Since she covered 27 miles while running and biking we have x + y = 27 8.5t1 + 16t2 =27 ------(1) t1 + t2 = 2 --------------(2) The simultaneous equation gives us t1 = 2/3 and t2 which is time she biked = 4/3 So 4/3 = 1 1/3. Which is 1 hour 20 minutes</span>
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Answer:

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Step-by-step explanation:

1) Data given and notation n  

n=100 represent the random sample taken

X=96 represent the laptop's arrived with fully charged batteries.

\hat p=\frac{96}{100}=0.96 estimated proportion of laptop's arrived with fully charged batteries.

p_o=0.85 is the value that we want to test

\alpha=0.05 represent the significance level  

z would represent the statistic (variable of interest)

p_v represent the p value (variable of interest)  

2) Concepts and formulas to use  

We need to conduct a hypothesis in order to test the claim that the new model’s rate is at least as high as the previous model.:  

Null hypothesis:p \leq 0.85  

Alternative hypothesis:p > 0.85  

When we conduct a proportion test we need to use the z statisitc, and the is given by:  

z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}} (1)  

The One-Sample Proportion Test is used to assess whether a population proportion \hat p is significantly different from a hypothesized value p_o.

3) Calculate the statistic  

Since we have all the info requires we can replace in formula (1) like this:  

z=\frac{0.96 -0.85}{\sqrt{\frac{0.85(1-0.85)}{100}}}=3.08  

4) Statistical decision  

P value method or p value approach . "This method consists on determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.  

The significance level is not provided, but we can assume \alpha=0.05. The next step would be calculate the p value for this test.  

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So based on the p value obtained and using the significance level assumed \alpha=0.05 we have p_v so we can conclude that we have enough evidenc to reject the null hypothesis, and we can said that at 5% of significance the proportion of new laptop's with fully charge for the new model is significantly higher compared to the old model.  

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Answer:

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Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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Hi!

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