MAT 2020 3.2 Assessment Task 3.2: Variance and Standard Deviation 100 points Use the following information for exercises 1 to 6. Suppose you want to know the variance of the weights of the only six snakes in a particular zoo. You measure their weights to be 8.3, 8.4, 8.6, 8.8, 9.2, and 9.5 pounds. 1. (8 points) Calculate the mean for the population: = __________ 2. (56 points; 4 points per cell) Fill in the following table: Weight Difference from the Mean ( ) (Difference from the Mean)2 ( )2 8.3 8.4 8.6 8.8 9.2 9.5 Total of the column: ( ) = ( )2 = 3. (8 points) Calculate the variance: 2 = ( )2 = __________ 4. (8 points) Now suppose those are the weights of six iguanas randomly selected from six different zoos. In that case, = from part (1). Calculate the variance of the sample: 2 = ( )2 1 = __________ 5. (8 points) The population standard deviation is the square root of the population variance. Calculate the population standard deviation using part (2): = 2 = ( )2 = __________ 6. (8 points) The sample standard deviation is the square root of the sample variance. Calculate the sample standard deviation using part (3):

MAT 2020 3.2 Assessment Task 3.2: Variance and Standard Deviation 100 points = 2 = ( )2 1 = __________ 7. (4 points) Find the sample variance for the following sample data. Round your answer to the nearest hundredth. x: 23, 20, 14, 32, 29 a. 41.04 b. 94.81 c. 51.30 d. 75.85