The article uncertainty estimation in railway track life- cycle cost (j. of rail and rapid transit, 2009) presented the following data on time to repair (min) a rail break in the high rail on a curved track of a certain railway line. 159 120 480 149 270 547 340 43 228 202 240 218 the sample mean and standard deviation are 249.7 and 145.1, respectively. is there compelling evidence for concluding that true average repair time exceeds 200 min? carry out a test of hypotheses using a significance level of α = 0.05.

1.) 2x + y = 3 2.) x - 2y = -1 if equation 1 is multiplied by 2 and then the equations are added, the result is a.3x = 2 b.3x = 5 c.5x = 5

Provide an example of a trigonometric function and describe how it is transformed from the standard trigonometric function f(x) = sin x, f(x) = cos x, or f(x) tan x using key features.

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.