Echocardiogram - Echo. 1  Problems with the outer lining of your heart (the pericardium). 2  Problems with the large blood vessels that enter and leave the heart. 3  Blood clots in the chambers of your heart. 4  Abnormal holes between the chambers of the heart.
(3) Select the smallest observed value as the lower limit of the first class (e.g. the left hand value for the first class), and add multiples of the class width from step (2) to obtain the lower limits for each class. So in the black bear case, the lower class limits would be. 16.0, 26.2, 36.4, 46.6, , 107.8. (4) Find the upper class limits (the right hand value for each class) by adding the class width to the lower class limits and subtracting from this the smallest significant digit in the observations.
Use a table of random numbers to determine the starting point for selecting every 40th subject. With list of the 2000 subjects in the sampling frame, go to the starting point, and select every 40th name on the list until the sample size is reached. Probably will have to return to the beginning of the list to complete the selection of the sample.