High Water Content Fruits. Watermelon and strawberries contain about 92 percent water per volume. Other fruits with high water content include grapefruit with 91 percent, cantaloupe with 90 percent and peaches with 88 percent water. Fruits containing 87 percent water by weight include pineapple, cranberries, orange and raspberries.
The sample variance sÂ² is the best point estimate (or single value estimate) of the population variance ÏÂ². The sample standard deviation s is commonly used as a point estimate of Ï ( even though it is a biased estimator). (Sec 6-4 showed that sÂ² is an unbiased estimator of ÏÂ², but s is a biased estimator of Ï.)
Hypothesis Test of Mean. for Normal Distribution (Sigma, Ï, is Known) - One Sample. Example: A sample of size 200 has a mean of 20. Assume the population standard deviation is 6. Use the TI-83 calculator to test the hypothesis that the population mean is not different from 19.2 with a level of significance of Î± = 5%. Solution: The population mean is not different from 19.2 means the same as the population mean is equal to 19.2. Therefore, the null and alternate hypotheses are H0:  = 19.2 and H1:  â  19.2, respectively.