q)9

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 ofthe 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 O 320 o I E -E 300 'E o a 3 280 .2 .- 3 o 260 ' 240 0 Exercise No exercise Treatment Using only the graph above, is it possible to predict the outcome ofa formal test of whether mean life span differs between the two treatments? (Yes/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.