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Rudik [331]
3 years ago
9

Ever since an automobile started to have a mechanical problem, every time it has burned a gallon of gasoline, it has traveled on

ly half as far as it did for the last gallon of gasoline it burned. If it traveled 40 miles for the first gallon of gasoline, it burned since the problem started, and if it has burned a total of 5 gallons of gasoline since the problem started, how many miles per gallon has the automobile averaged since the problem started?
A)
15 miles per gallon


B)
15.5 miles per gallon


C)
16 miles per gallon


D)
16.5 miles per gallon
Mathematics
1 answer:
kati45 [8]3 years ago
3 0
B. The amount of distance it traveled for 5 gallons is 77.5 mi as 40+20+10+5+2.5 so divide that by 5 and you get 15.5
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Answer:

Step-by-step explanation:

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Null and alternative hypothesis is computed as follows:

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H₁: There is a difference in the proportions of polio cases between both groups.

Let assume that the level of significance ∝ = 0.05

The test statistic  can be computed as:

Z = \dfrac{\hat p_1-\hat p_2}{\sqrt{\dfrac{\hat p_1 \hat q_1}{n_1}+ \dfrac{\hat p_2 \hat q_2}{n_2}}}

Z = \dfrac{0.000285-0.000710}{\sqrt{\dfrac{0.000285(1-0.000285)}{200000}+ \dfrac{0.000710(1-0.000710)}{200000}}}

Z = \dfrac{-4.25\times 10^{-4}}{\sqrt{\dfrac{0.000285(0.999715)}{200000}+ \dfrac{0.000710(0.99929)}{200000}}}

Z = - 6.03

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From the Z - tables

P-value =  2 × 0.0000

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We reject the H₀ provided that P-value is very less.

Therefore, we may conclude that there is a difference in the proportions of polio cases between the vaccine group and placebo group not due to chance.

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Lera25 [3.4K]

Answer:

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