A nutritionist suspected that her company's clients had below average cholesterol. They obtained a random sample of 8 clients of the same age and gender. These clients had a mean cholesterol level of xˉ=4.28 mmol/L (millimoles per liter).
To see how likely a sample like this was to happen by random chance alone, the nutritionist performed a simulation. They simulated 60 samples of n=8 cholesterol levels from a normal population with a mean of 4.6 mmol/L and a standard deviation of 0.5 mmol/L (these are generally accepted values for people with the same age and gender of those in the sample). They recorded the mean of the cholesterol levels in each sample. Here are the sample means from their 60 samples:

They want to test H0:μ=4.6 mmol/L vs. Ha:μ<4.6 mmol/L where μ is the mean cholesterol level for all clients like those sampled.

Based on these simulated results, what is the approximate p-value of the test?
Note: The sample result was xˉ=4.28 mmol/L.