A rocket motor is manufactured by bonding together two types of propellants, an igniter and a sustainer. A random sample of 26 specimens is used to investigate the relationship between the shear strength of the bond in psi and the age of the propellant in weeks. Below is the R output for the estimated linear regression. Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 2609.2 37.4 69.765