The scores X1 and X2 in papers 1 and 2 of an examination are normally distributed with means 24.3 and 31.2 respectively and standard deviations 3.5 and 3.1 respectively The final mark for each candidate is found by calculating 2X1+1.5X2. Find the probability that a random sample of 8candiates will have a mean final mark of less than 60.(adsbygoogle = window.adsbygoogle || []).push({});

what i have done so far is F~N(95.4,70.6225) and Sample mean of F, N (95.4,70.6225/8)

P(sample mean of F<60)

... then unable to do alrdy because the z-score is too large

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# Sampling- linear combinations

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