A doctor says the SD of the lengths of stay for patients involved in a crash is 6.14 days. A random sample of 20 patients involved in this type of crash has a SD of 6.5 days. At alfa=0.05, can you reject the doctor's claim?
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(n-1)s^2/(Var) has a chi-square distribution with (n-1) deg. Freedom.
So 19(6.5)^2/(6.14)^2=21.29 has a chi-square dist with 19 df.
Critical value is 30.14, so do not reject doctor's claim,
So 19(6.5)^2/(6.14)^2=21.29 has a chi-square dist with 19 df.
Critical value is 30.14, so do not reject doctor's claim,