Question

Spinocerebellar ataxia type 1 is a neurodegenerative disease marked by the gradual loss of motor skills and culminating in early death. It is caused by an expanded CAG repeat in the coding region of the Ataxin-1 gene. Fryer et al. (2011) investigated the possible beneficial effects of exercise in treating the disease. They used a mild exercise regimen in a mouse model of the disease (a mouse strain in which the expanded CAG repeat was "knocked in" to the mouse version of the same gene, and that had similar symptoms). The life spans (in days) are given below for six exercised mice and six mice not given the exercise regimen. The data and 95% confidence intervals are shown in the accompanying graph. No exercise: 240, 261, 271, 275, 276, 281 Exercise: 261, 293, 316, 319, 324, 347 340 320- 300- n280 260 240 Exercise No exercise Treatment Using only the graph above, is it possible to predict the outcome of a formal test of whether mean life span differs between the two treatments? ?es/No) How many days does exercise increase the life span on average? Use a confidence interval to answer this question. Round your answers to whole numbers.

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Answer 1

Answer Date: 03/04/2018 Using only the graph above, it is possible o predict outcome of formal test of whether mean life span differs between the two treatment due to the shape of distribution is approximately normal, no outlier and t test robust A 95% confidence interval for the number of days exercise increase the life span of average is By using MINITAB, find confidence interval with the help of the following steps: 1) Import the data. 2) Select the Stat and choose the Basic Statistics option 3) Select the 2 sample t and enter Summarized data. 4)Click option button choose Confidence level, Test difference and alternative hypothesi:s. 5) Click Ok.

Two-Sample T-Test and Cl: No exercise, Exercise Iwo-sample T for No exercise vs Exercise No exercise 6 267.3 15.0 Exercise 6 310.0 29.6 N Mean StDev SE Mean 6.1 12 Difference = mu (No exercise) -mu (Exercise) Estimate for difference: 42.7 95% CI for difference: (-74.7, -10.7) From the MINITAB output, a 95% confidence interval for the number of days exercise increase the life span of average is-75 to 11