The gestation time of humans has an approximate Normal distribution with a mean of 250 days and a standard deviatim- 6.0 days. A simple random sample of n newborns is to be taken.What is the minimum sample sized needed so that the sampling distribution of xˉ has a standard deviation of 0.5 day?1514412250
Q. The gestation time of humans has an approximate Normal distribution with a mean of 250 days and a standard deviatim- 6.0 days. A simple random sample of n newborns is to be taken.What is the minimum sample sized needed so that the sampling distribution of xˉ has a standard deviation of 0.5 day?1514412250
Identify Formula: Step 1: Identify the formula to find the minimum sample size needed to achieve a specific standard deviation of the sample mean. The formula is n=(desired standard deviationσ)2 where σ is the population standard deviation.
Plug in Values: Step 2: Plug in the values into the formula. Here, σ=6.0 days (given as the standard deviation of the population), and the desired standard deviation of the sample mean is 0.5 day. So, n=(0.56.0)2.
Calculate Inside Parentheses: Step 3: Calculate the value inside the parentheses first. 0.56.0=12.0.
Square Result: Step 4: Now, square the result from Step 3 to find n. 12.02=144.
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