what is the rule?

x 5 7 9 11
y 1 1.6 1.8 2.2

To determine the rule for the given sequence of numbers:

1. Look for a pattern in the relationship between the x-values and y-values.
2. Calculate the differences or ratios between consecutive x-values and y-values.
3. Identify any consistent pattern in these differences or ratios.

Let's examine the differences between consecutive x-values:

7 - 5 = 2
9 - 7 = 2
11 - 9 = 2

We observe that the differences between consecutive x-values are all 2.

Now, let's examine the differences between consecutive y-values:

1.6 - 1 = 0.6
1.8 - 1.6 = 0.2
2.2 - 1.8 = 0.4

Here, the differences between consecutive y-values are not consistent.

Since the differences between consecutive x-values are consistent (2), we can conclude that the rule for this sequence is adding 2 to each x-value to get the corresponding y-value.

Therefore, the rule is:
y = x + 2