Structural engineers use wireless sensor networks to monitor the condition of da
ID: 3362782 • Letter: S
Question
Structural engineers use wireless sensor networks to monitor the condition of dams and bridges. An article describes an experiment in which accelerometers were placed on the Golden Gate Bridge for the purpose of estimating vibration modes. The following output (from MINITAB) describes the fit of a linear model that predicts the frequency (in Hz) in terms of the damping ratio for over damped (damping ratio > 1) modes. There are n = 7 observations.
Someone claims that the frequency decreases by 0.6 Hz if the damping ratio increases by 1. Use the given output to perform a hypothesis test to determine whether this claim is plausible.
FIND P Value!! P is greater than 0.80, P is greater than 0.10 and less than 0.20, P is less than 0.001, P is greater than 0.50 and less than 0.80, P is greater than 0.001 and less than 0.002, P is greater than 0.20 and less than 0.50, P is greater than 0.02 and less than 0.05, P is greater than 0.05 and less than 0.10, or P is greater than 0.002 and less than 0.01. Choose ONE.
The regression equation is Frequency = 0.773-0.280 Damping Ratio Predictor Constant Damping Ratio -0.27985 0.079258 Coef 0.77289 SE Coef 0.14534 5.3176 0.003 -3.5309 0.017Explanation / Answer
H0: the frequency not decreases by 0.6 Hz
H1: the frequency decreases by 0.6 Hz
The p-value of Damping Ratio is 0.017 which is less than 0.05, so we reject H0
thus we conclude that the frequency decreases by 0.6 Hz