Question

A machine that cuts corks for wine bottles operates in such a way that the distribution of the diameter of the corks produced is well approximated by a normal distribution with mean 2 cm and standard deviation 0.1 cm. The specifications call for corks with diameters between 1.9 and 2.1 cm. A cork not meeting the specifications is considered defective. (A cork that is too small leaks and causes the wine to deteriorate; a cork that is too large doesn't fit in the bottle.) What proportion of corks produced by this machine are defective

Answer 1

The proportion of defective corks produced by this machine through z test comes out is 0.320.

Given mean of 2 cm and standard deviation of 0.1 cm, The diameter is between 1.9 and 2.1 cm.

We have to find the proportion of defective corks that are produced by machine.

In this problem we have to first find z score and then we will be able to find the probability of defective corks produced by the machine.

Z=(X-μ)/σ

μ=2 cm and σ=0.1 cm.

Z value corresponding to X=1.9.

Z=(1.9-2)/0.1

=-0.1/0.1

=-1

Z value corresponding to X=2.1.

Z=(2.1-2)/0.1

=0.1/0.1

=1

P value of P(-1<Z<1)=2*0.3410=0.6820

Proportion of corks which are not defective=0.6820.

Proportion of corks which are defective=1-0.680.

=0.320

Hence the proportion of defective corks produced by machine is 0.320.

Learn more about z test at brainly.com/question/14453510

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