HYPOTHESIS TEST
1.The maximum safe level of bacteria per ml sample of water is 50. suppose that 60 samples of water are taken randomly from our water source. for this 60 observatations, the average bacteria content is 51.7 bacteria per ml, with a standard deviation of 7 bacteria per ml.
2.In a sample of 46 people. we find the average blood glucose level upon waking up is 5.3 mmol/L with a standard deviation of 1.2 mmol/L. is there reason to believe that the true mean blood glucose level upon waking for people is not 5 mmol/L?
3.
| A researcher wishes to test the following hypotheses: H0: μ = 120. with α = 0.05. He carefully takes a sample and obtains: n = 40, X = 105.37, s = 32.17 What is the appropriate conclusion? |
4.The college bookstore tells prospective students that the average cost of its textbooks is $52 with a standard deviation of $4.50. A group of smart statistics students thinks that the average cost is higher. In order to test the bookstore’s claim against their alternative, the students will select a random sample of size 100. Assume that the mean from their random sample is $52.80. Perform a hypothesis test (6 step procedure outlined in class) at the 5% level of significance and state your decision.
5.A certain chemical pollutant in the Genesee River has been constant for several years with mean μ = 34 ppm (parts per million) and standard deviation σ = 8 ppm. A group of factory representatives whose companies discharge liquids into the river is now claiming that they have lowered the average with improved filtration devices. A group of environmentalists will test to see if this is true at the 4% level of significance. Assume that their sample of size 50 gives a mean of 32.5 ppm. . Perform a hypothesis test (6 step procedure outlined in class) at the 4% level of significance and state your decision