An insurance company, based on past experience, estimates the mean damage for a natural disaster in its area is $5,000. After introducing several plans to prevent loss, it randomly samples 200 policyholders and finds the mean amount per claim was $4,800 with a standard deviation of $1,300. Does it appear the prevention plans were effective in reducing the mean amount of a claim? use the 0. 05 significance level. A. What is the decision rule? (negative amount should be indicated by a minus sign. Round your answer to 3 decimal places. )