Question

An article reported that patients under care for HIV have CD4 tests every 4 months on...

An article reported that patients under care for HIV have CD4 tests every 4 months on average with a standard deviation of 1.5 months. What is the probability that in a sample of 60 patients, the mean time between tests exceeds 4.5 months?

Homework Answers

Answer #1

Solution :

Given that ,

mean = = 4

standard deviation = = 1.5

n = 60

= 4

= / n = 1.5 / 60 = 0.19365

P( >4.5 ) = 1 - P( <4.5 )

= 1 - P[( - ) / < (4.5-4) / 0.19365]

= 1 - P(z <2.58 )

Using z table

= 1 - 0.9951

= 0.0049

probability= 0.0049

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