Question

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A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly at the 431 gram setting. It is believed that the machine is underfilling the bags. A 26 bag sample had a mean of 427 grams with a standard deviation of 20. A level of significance of 0.1 will be used. Assume the population distribution is approximately normal. Is there sufficient evidence to support the claim that the bags are underfilled?

Answer 1

n =26

S =20

Null and alternative hypothesis is

Level of significance = 0.1

Here population standard deviation is not known so we use t-test statistic.

Test statistic is

Degrees of freedom = n - 1 = 26-1=25

P-value = 0.1588 ( using t table)

P-value ,Failed to Reject H0

conclusion : At ,there is insufficient evidence to conclude that the machine is underfilling the bags.