Quiz4 - 1. From past records it is known that the average...

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1. From past records it is known that the average life of a battery used in a digital clock is 305 days. The battery life is normally distributed. The battery was recently modified to last longer. A sample of 20 of the modified batteries was tested. It was discovered that the mean life was 311 days and the sample standard deviation was 12 days. We want to test at the 0.05 level of significance whether the modification increases the life of the battery. What is our decision rule? (Points : 1) Do not reject the null hypothesis if computed t is 1.96 or greater Reject the null hypothesis if computed t is less than 1.96 Do not reject the null hypothesis if computed t is 1.729 or greater Reject the null hypothesis if computed t is 2.086 or greater None of these 2. What is the critical value for a one-tailed hypothesis test in which a null hypothesis is tested at the 5% level of significance based on a sample size of 25? (Points : 1) 1.708 1.711 2.060 2.064 3. A manufacturer of stereo equipment introduces new models in the fall. Retail dealers are surveyed
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Quiz4 - 1. From past records it is known that the average...

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