Question

An important feature of modern tablets is battery life. Here, we wish to compare how tow popular tablets brands perform in this area. You collect a sample of 16 Ipad tablets and 13 Surface tablets. The ipad sample had a mean of 600 minutes of battery life, with a standard deviation of 6.88 minutes. Meanwhile, the Surface sample had a mean of 625 minutes and a standard deviation of 6.03 minutes. We wish to know if the Ipad tablets have a higher variance in battery life than the Surface tablets. Battery life has a normal distribution in both populations, and you are asked to use α = 0.05.

Answer 1

i am denoting the ipad tablets by group 1 and surface tablets by group 2.

given data are:-

hypothesis:-

[ claim ]

the test statistic be:-

df₁ = (n₁-1) = (16-1) = 15, df₂ = (n₂-1) = (13-1) = 12,

the p value = 0.3266

[ in any blank cell of excel type =F.DIST.RT(1.3018,15,12) ]

decision:-

p value = 0.3266 > 0.05(alpha)

we fail to reject the null hypothesis. There is not enough evidence to claim that , the Ipad tablets have a higher variance in battery life than the Surface tablets.

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