Figure 1 shows an algorithm Chloe has written using pseudocode to calculate the mean of a series of temperature readings.

Chloe uses the input sequence 10, 20, 30, -99 to test her algorithm, where -99 is the sentinel value used to stop input.

Figure 1

1  SET total TO 0
2  SET temp TO 0
3  SET count TO 0
4  WHILE temp <> -99 DO
5      SEND 'Enter temperature (or -99 to stop):' TO DISPLAY
6      RECEIVE temp FROM (INTEGER) KEYBOARD
7      SET total TO total + temp
8      SET count TO count + 1
9  END WHILE
10 SET mean TO total / count
11 SEND 'The mean temperature is ' & mean TO DISPLAY

Test Results Table