Question 4 [25]
The Zambezi car battery manufacturer claims that the averagelifespan of batteries produced by his firm is at least 30 months.The rival manufacture the Rehoboth batteries disagree and tookrandom sample of 100 Zambezi car batteries and recorded a mean of31.7 months and a standard deviation of 8 months. (Show all yourworks)
Determine the following:
a) The null and alternative hypotheses
b) The test statistic value.
c) The critical statistics value at 99% confidence level
d) The rejection region using critical value approach
e) The p value at 99% confidence level
f) The rejection region using both the p value approach
g) Make conclusion about the population mean using bothapproaches
