I'm struggling to get the solution for this question.
Steel bolts of circular cross section are to be produced. The lengths of the bolts have to lie between 64.5 and 65.4 mm, and their diameters have to be between 5.5 and 6.0 mm. A machine produces these bolts so that their lengths are normally distributed with a mean of 65.4 mm and a standard deviation of 0.5 mm and their diameters are independently normally distributed about a mean of 5.7 mm with standard deviation σ.
If 1000 bolts are made, how many bolts will not be within the specified limits for length?
If 50 bolts have a diameter greater than 6.0 mm, what is the value of σ?
2007-05-18 09:49:40 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
If the mean length is 65.4, equal to the specified limit, 50% of the bolts will not be within the specified limit for length.
If 50/1000 or 0.05 bolts have a diameter greater than 6 mm then 6 mm = 5.7 + 1.6449σ
σ = 0.182 mm
2007-05-18 11:05:39 · answer #1 · answered by Helmut 7 · 0⤊ 0⤋
zero.....and why do you care? ask a machinist
2007-05-18 10:01:57 · answer #2 · answered by Anonymous · 0⤊ 2⤋