Mechanical engineer Behnam Amin has developed an "intelligent" liquid flow valve using a miniature embedded microprocessor that harnesses the power of advanced modular electronics to control the flow. The response time of the control valve had a mean of 2.17 seconds with a standard deviation of 0.472 after performing 25 tests on the control valve. These valves are used in applications such as aircraft fuel-tank level control systems.
Construct a 99% confidence interval for the population mean response time.
|Confidence interval statistics|
|Find a zc value from a confidence level c||zc||=ABS(NORMSINV((1-c)/2))|
|Find a tc value from a confidence level c and sample size n||tc||=TINV(1-c,n-1)|
|Calculate an error tolerance E of a mean for n >= 30 using sx||E||=zc*sx/SQRT(n)|
|Calculate an error tolerance E of a mean for n < 30 using sx. Can also be used for n >= 30.||E||=tc*sx/SQRT(n)|
|Calculate a confidence interval for a population mean µ from a sample mean x and an error tolerance E||x-E<= µ <=x+E|