101k views
5 votes
Researchers at a drug company are testing the duration of a new pain reliever. The drug is normally distributed with a mean duration of 240

minutes (4
hours) and a standard deviation of 40
minutes. The drug is administered to a random sample of 10
people. (Round means, standard deviations, and z
-scores to the nearest hundredth, if necessary.)

1 Answer

1 vote

There is approximately a 94.32% probability that the duration of the new pain reliever for a random sample of 10 people is less than 260 minutes, based on a mean of 240 minutes and a standard deviation of 40 minutes.

To determine the probability of the drug's duration for a random sample of 10 people, we can use the normal distribution. Given a mean (μ) of 240 minutes and a standard deviation (σ) of 40 minutes, we can calculate the standard error of the mean (SEM) using the formula:

SEM = σ / sqrt(n)

where n is the sample size. For this scenario, n = 10.

SEM = 40 / sqrt(10) ≈ 12.65

Now, to find the probability, we convert the duration to a z-score using the formula:

z = (X - μ) / SEM

Assuming we want to find the probability of the drug lasting less than 260 minutes:

z = (260 - 240) / 12.65 ≈ 1.58

Consulting a standard normal distribution table or calculator, we find the corresponding probability. In this case, it's approximately 0.9432.

Therefore, there's about a 94.32% probability that the drug's duration for a random sample of 10 people is less than 260 minutes.

User GriffLab
by
8.0k points