A hint to get started
Interpret a probability inequality as a range of mass thresholds
Chain-link mass is normal with mean 800 g and standard deviation 20 g.
(i) Find the probability one link exceeds 805 g. mark
A locking sleeve increases the link’s mass by 10%.
(ii) State the sleeved-link mass distribution and find the probability it lies between 865.35 and 895.5 g. marks
Hook mass is normal with mean 750 g;15% weigh below 735.6 g.
(iii) Find its standard deviation. marks
Five independent sleeved links and one hook are packed in a fixed 1 kg wooden box. The probability that the box and contents exceed k grams is more than 0.013.
(iv) Find k to 1 decimal place, stating all distribution parameters used. marks
[2018/NYJC/Prelim/8(modified)]
CJC · Review problems · Question 10
A fixed 1 kg box adds 1000 g to the mean and no variance.