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S1 Question (Normal distribution)

The weight in grams, of beans in a tin is normally distributed with mean mu and std deviation 7.8.

The machine settings are adjusted so that the weight, in grams, of beans in a tin is normally distributed with mean 205 and standard deviation sigma.

given that 98% of tins contain between 200g and 210g find the value of sigma.

How do i go about this? thanks :smile:

Reply 1

Smaug123

Original post by Mr Tall

Probability(200 < z < 210) = 0.98, where z follows N(205, sigma).
Can you transform the left-hand side so that it's Probability(something < z < something else), where z follows N(0,1), so that you can look the answer up in tables?