To find the equivalent one-tailed p-value from a two-tailed p-value, you typically divide the two-tailed p-value by 2. In this case, if you have a two-tailed p-value of 0.04:
Equivalent one-tailed p-value = 0.04 / 2 = 0.02
So, the equivalent one-tailed p-value would be 0.02.