A highly sensitive device used to measure electricity activity in the brain is required to have a variance in measurements not exceeding 0.0001 volts^2. if the variance exceeds this tolerance, the device has to be serviced and re calibrated. A sample of 24 measurements taken with the device was found to have a variance of 0.000144 volts^2. Test at the 5% significance level to see if there is an increase in the variability.