Suppose you are dog breeder and you want to use a confidence interval to estimate the true mean fertility levels of purebred coc
ker spaniels. it is known that the distribution of fertility levels of cocker spaniels is normal. how many measurements must you have in order to be sure the sampling distribution of x¯ {"version":"1.1","math":"\bar{x}"} is normal?
According to the Central Limit Theorem the sum or average of at least 30 independent random variables with the same distribution is approximately normal. Therefore the answer is 'at least 30 measurements.'
The Central Limit Theorem estabilishes that, for a random variable X, with mean and standard deviation , a large sample size, of at least 30, can be approximated to a normal distribution with mean and standard deviation .
There is no possible answer. The #s are 420, 480, and 540. None of them are 40 away from a multiple of 100. However, it is was between 300 and 600, the answer would be 360.
