Hi,   I have the following data:   Size Value 1  .  2  .  3      8.00 4      7.40 5      7.20 6  .  7  .  8  .  9      6.80 10  .  11  .  12      5.90 13  .  14  .  15  .    I want to calculate the missing values from the available values. For instance, values for sizes 1 and 2 are missing. The nearest available values are for sizes 3 and 4, and the values are 8.00 and 7.40. The difference in these sizes is 1 and the difference in the value is 0.60. Therefore the value of size 2 is 8.60 (that is, value of preceding size 3 at 8.00 plus the difference of 0.60) and the value of size 1 is 9.20 (that is, value of size 2 at 8.60 plus difference of 0.60). Similarly the values of sizes 6, 7 and 8 are calculated from the available values of sizes 5 and 9 as follows. The difference in the sizes is 4 and the difference of available values is 0.40 (that is, the size 5 value is 7.20 and size 9 value is 6.80) and the difference per size is 0.10 (that is, 0.40 divided by 4). Therefore the values of 6, 7 and 8 are 7.10, 7.00 and 6.90 respectively. The result will be like this.   Size Value 1      9.20 2      8.60 3      8.00 4      7.40 5      7.20 6      7.10 7      7.00 8      6.90 9      6.80 10      6.50 11      6.20 12      5.90 13      5.60 14      5.30 15      5.00   Will someone please let me know how to write a program for this in SAS 9.4?   Thanks.   ... View more