Question

Please help with work shown!! Greatly appreciated!

Question 2) In order for a spark plug to work optimally the spark plug mean gap should be exactly 0.25 inches. A company conducts a quality control check by selecting a simple random sample of 40 spark plugs with a sample mean of 0.254 inches and a sample standard deviation of 0.012 inches. ( assume the population of gap measurements is normally distributed)

2a) Does this sample provide sufficient evidence that the population gaps are not .25 inches at the 10% significance level? (Circle either YES or NO)

2b) Show the four steps of your analysis in the space provided below:

Step 1) State the null and alternate Hypothesis,

Step 2) Determine the rejection region( Use either classical approach or p value approach).

Step 3) Calculate the test statistic and determine the p-value of the test.

Step 4) Conclude with either "reject H₀" or "do not reject  H₀ "

Answer 1

2 sa) Yes Stap Null apothesrs to: -025 A Hternative H3pothesrs Ha to.25 : &tep Rejeolion vegien y churcal approaehis J지 > Za, (tuo tatl녀 test) at loA &tp3: Test &tateshre 0.0174 Ze2-11 Here 121 o이니시R이 -254-025 6.014K2 O03 4858 Pvalue e tesl 164, the null lene! et rgweruaute By classrcal apreaut) ORdaeP valee Anzpotien's rejated at lo 03 480 to Clenl Svgafreau Rejut Ho: hEo25