A study shows 70% of consumers believe cheaper supermarket brands are just as good as national name brands. In response to these findings, the manufacturer of a national brand asked a sample of shoppers whether they believe that supermarket chutney was as good as the national brand chutney. A sample of 150 shoppers was tested and 90 believe that the supermarket brand is just as good as the national brand. Calculate the z-value, round the answer to decimal places? Also give the statistical conclusion for the test, use a 90% significance level? And lastly, should the national brand chutney manufacturer be pleased with the management conclusion? Explain