A researcher used previous research to propose a prior distribution over the values of a parameter. The range of possible values for that parameter is 0-120. The mean in previous studies was 60, with some studies showing slightly higher and slightly lower means. Which of the following prior distributions did she most likely use?

1. A normal distribution with a mean of 60 and a standard deviation of 30.
2. A beta distribution.
3. A uniform distribution over values from 0 to 120.
4. A normal distribution with a mean of 60 and a standard deviation of 6.
5. A normal distribution with a mean of 30 and a standard deviation of 6.