This is a problem about sampling distribution that got me a little confused.. The time it takes for students to complete their university degrees has a distribution normal mean 6,4 years and standard deviation 2,4 years. If a random sample of 50 students, find the probability that the mean time to complete the course is greater than 5 years.

What I've done so far is: P(x > 5) σ= 2,4 µ= 6,4 z= 5-6,4/ (2,4/√60)= -4,51 and I dont know where to go from there, any help would be appreciated, thank you in advance.

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  • $\begingroup$ Why do you have √60 in that z formula? Watch your order of operations as well, you need ( $\cdot$ ) around the numerator in that z expression $\endgroup$
    – Glen_b
    May 14 at 9:22


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