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an =A population of values has a normal distribution with y = 218.4 and o = 86.3. A random sample of size167 is drawn. Find the probability that a sample of size n = 167 is randomly selected with a mean lessthan 220.4. Round your answer to four decimal places.PM <220.4)

User Herodrigues
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1 Answer

10 votes
10 votes

Given:


\mu=218.4,\sigma=86.3.n=167\text{ and M=220.4}

The z-score value is


z=\frac{M-\mu}{\frac{\sigma}{\sqrt[]{n}}}


\text{Substitute }\mu=218.4,\sigma=86.3.n=167\text{ and M=220.4, we get}


z=\frac{220.4-218.4}{\frac{86.3}{\sqrt[]{167}}}


z=\frac{\sqrt[]{167}(220.4-218.4)}{86.3}


z=0.29949

The P-value from the z-table is


P(218.4[tex]P(M<220.4)=0.11772+0.5


P(M<220.4)=0.61772

Hence the answer is


P(M<220.4)=0.61772

User Piyush Patil
by
2.8k points
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