Step 3: Place parentheses around the numbers above and below the median. Not necessary statistically, but it makes Q1 and Q3 easier to spot. (1, 2, 5, 6, 7), 9, (12, 15, 18, 19, 27).
Step 4: Find Q1 and Q3 Think of Q1 as a median in the lower half of the data and think of Q3 as a median for the upper half of data. (1, 2, 5, 6, 7), 9, ( 12, 15, 18, 19, 27). Q1 = 5 and Q3 = 18.
Step 5: Subtract Q1 from Q3 to find the interquartile range. 18 – 5 = 13.
The first thing I would do is convert that 1.2 kilograms of salt to grams; that would ensure that all the units are the same so we can perform calculations on them.
1.2kg = 1200g
Next, I would find out how many students can do the experiment with 1200g of salt, by finding it how many 25g are in 1200g (by dividing them).
That means we still have 80 students left to provide salt for (128 - 48). Therefore, he needs an additional 80 amounts of 25g of salt.