The following are the weights, in decagrams, of 10 packages of grass seed distributed by a...

The following are the weights, in decagrams, of 10 packages of grass seed distributed by a certain company: 46.4, 46.1, 45.8, 47.0, 46.1, 45.9, 45.8, 46.9, 45.2, and 46.0. Find a 95% confidence interval for the standard deviation of the weights of all such packages of grass seed distributed by this company, assuming a normal population.

Expert Solution

Solution :

Summary statistics:

Column	Variance	n
data	0.28622222	10

s² = 0.2822

²_L = ²_/2,df = 19.023

²_R = ²_{1 -} _/2,df = 2.700

The 95% confidence interval for is,

(n - 1)s² / ²_/2 < < (n - 1)s² / ²_{1 -} _/2

9 * 0.2822 / 19.023 < < 9 * 0.2822 / 2.700

0.37 < < 0.98

(0.37 , 0.98)

orchestra answered 2 years ago

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