An architect estimates that the average height of the buildings of 30 or more stories in Suva

is at least 500 feet. A random sample of 12 buildings is selected, and the heights in feet are
shown. At  = 0.025, is there enough evidence to reject the claim?

634 385 411 741 625 515
345 420 435 535 516 482

Find the mean first = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

Z = (score-mean)/SEm

SEm = SD/√n

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

I'll let you do the calculations.