sample data that the average grade in Maine significantly lower than 88 %. e ed ACTIVITY 1: is 1. A factory, manufacturing light-emitting diode (LED) bulbs, claims that the average lifespan of their light bulbs is 50, 000 hours. To confirm if this claim is valid, a quality control manager got a sample of 50 LED bulbs and obtained a mean lifespan of 40, 000 hours. The standard deviation of the manufacturing process is 1, 000 hours. Do you think the claim of the manufacturer is valid at the 5% level of significance? STEP 1. Formulate the null and alternative hypotheses. Ho: Ha: STEP 2. Specify the level of significance and choose the appropriate statistical tool. STEP 3. Compute the test statistic. Given: x = Up = 0= 1 =STEP 4. Establish a critical region. Point estimate is a single value the parameter, such as & as estimate for Interval estimate sometimes called confidence interval, is a range or interval (with Cont lower and upper limits) used to estimate the population parameter. It is usually in the form a