{"id":879,"date":"2022-01-16T18:10:37","date_gmt":"2022-01-16T23:10:37","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/statspsych\/?post_type=chapter&p=879"},"modified":"2024-04-05T14:35:11","modified_gmt":"2024-04-05T18:35:11","slug":"worksheet-2b","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/statspsych\/chapter\/worksheet-2b\/","title":{"raw":"Worksheet 2b.","rendered":"Worksheet 2b."},"content":{"raw":"These guided exercises will give you the opportunity to practice the techniques and apply the concepts you learned in Chapter 2b. You will need some paper, spreadsheet, or a tablet to work on the analyses.\r\n
    \r\n \t
  1. Data collected from hospital records reveal that the age of first hospitalization for psychosis for a sample of patients are:<\/li>\r\n<\/ol>\r\n

    18, 20, 21, 22, 23, 23, 24, 28, 28, 29, 32, 37, 39<\/p>\r\n

    a. Calculate the variance for this dataset using the formula below.<\/p>\r\n

    [latex] \\[SD^{2}=\\frac{\\sum (X-M)^{2}}{N}\\] [\/latex]<\/p>\r\n\r\n

      \r\n \t
    1. \r\n
      \r\n

      Steps to Calculate Variance<\/span><\/p>\r\n\r\n<\/header>\r\n

      \r\n
        \r\n \t
      1. Take the distance (\u201cdeviation\u201d) of each score from the mean<\/li>\r\n \t
      2. Square each distance to get rid of the sign (because some deviations will be negative)<\/li>\r\n \t
      3. Add up all the resulting \u201csquared deviations\u201d to get Sum of Squares (SS)<\/li>\r\n \t
      4. Divide by the number of scores<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n[h5p id=\"116\"]\r\n\r\n[h5p id=\"117\"]\r\n\r\nb. Calculate the standard deviation for this dataset using the formula below.<\/li>\r\n<\/ol>\r\n

        [latex] \\[SD=\\sqrt{SD^{2}}\\] [\/latex]<\/p>\r\n

        [h5p id=\"118\"]<\/p>\r\n

        [h5p id=\"119\"]<\/p>\r\n

        [h5p id=\"120\"]<\/p>\r\n\r\n

          \r\n \t
        1. The number of years of education for most members of the sample in the study of psychosis onset were:<\/li>\r\n<\/ol>\r\n

          6, 7, 9, 10, 11, 12, 12, 13, 13, 13, 15, 16<\/p>\r\n

          a. Calculate the variance for this dataset using the formula below.<\/p>\r\n

          [latex] \\[SD^{2}=\\frac{\\sum (X-M)^{2}}{N}\\] [\/latex]<\/p>\r\n

          [h5p id=\"121\"]<\/p>\r\n\r\n

            \r\n \t
          1. b. Calculate the standard deviation for this dataset using the formula below.<\/li>\r\n<\/ol>\r\n

            [latex] \\[SD=\\sqrt{SD^{2}}\\] [\/latex]<\/p>\r\n

            [h5p id=\"122\"]<\/p>\r\n\"\"\r\n

            [h5p id=\"123\"]<\/p>\r\n

            [h5p id=\"124\"]<\/p>","rendered":"

            These guided exercises will give you the opportunity to practice the techniques and apply the concepts you learned in Chapter 2b. You will need some paper, spreadsheet, or a tablet to work on the analyses.<\/p>\n

              \n
            1. Data collected from hospital records reveal that the age of first hospitalization for psychosis for a sample of patients are:<\/li>\n<\/ol>\n

              18, 20, 21, 22, 23, 23, 24, 28, 28, 29, 32, 37, 39<\/p>\n

              a. Calculate the variance for this dataset using the formula below.<\/p>\n

              \n

                <\/span>   <\/span>\" \[SD^{2}=\frac{\sum (X-M)^{2}}{N}\] \"<\/p>\n

                \n
              1. \n
                \n
                \n

                Steps to Calculate Variance<\/span><\/p>\n<\/header>\n

                \n
                  \n
                1. Take the distance (\u201cdeviation\u201d) of each score from the mean<\/li>\n
                2. Square each distance to get rid of the sign (because some deviations will be negative)<\/li>\n
                3. Add up all the resulting \u201csquared deviations\u201d to get Sum of Squares (SS)<\/li>\n
                4. Divide by the number of scores<\/li>\n<\/ol>\n<\/div>\n<\/div>\n
                  \n