In: Statistics and Probability
In the 1990s, it was generally believed that genetic
abnormalities affected about 5% of a large nation's children. Some
people believe that the increase in the number of chemicals in the
environment has led to an increase in the incidence of
abnormalities, which could have important implications for health
insurance companies. A recent study examined 366 randomly selected
children and found that 26 of them showed signs of a genetic
abnormality.
(a) Which hypotheses should be used to test if the proportion of
genetic abnormalities has increased in recent years?
H0: p = 0.05 vs. Ha: p < 0.05H0: p = 0.05 vs. Ha: p ≠ 0.05 H0: p = 0.0710 vs. Ha: p < 0.0710H0: p = 0.0710 vs. Ha: p ≠ 0.0710H0: p = 0.05 vs. Ha: p > 0.05H0: p = 0.0710 vs. Ha: p > 0.0710
(b) Are the conditions met for doing the hypothesis test?
The 15 successes and failures condition is met. The children taking part in the study were independent of each other.The sample was randomly chosen.None of the conditions are met.
(c) What is the p-value? (Use 3 decimals.)
(d) What does this p-value mean?
The p-value is the chance of observing 26 or more children with genetic abnormalities in a random sample of 366 children, if the true proportion of children with genetic abnormalities is 5%.The p-value is the chance of observing 5% of children with genetic abnormalities. The p-value gives the actual percentage of children who have genetic abnormalities.The p-value is the chance of observing 26 or more children with genetic abnormalities in a random sample of 366 children, if the true proportion of children with genetic abnormalities is 7.1%.
(e) What is the conclusion of the hypothesis test, for α =
0.05?
Reject H0. There is sufficient evidence that more than 5% of this nation's children have genetic abnormalities.Reject H0. There is insufficient evidence that more than 5% of this nation's children have genetic abnormalities. Do not reject H0. There is sufficient evidence that more than 5% of this nation's children have genetic abnormalities.Do not reject H0. There is insufficient evidence that more than 5% of this nation's children have genetic abnormalities.
(f) Do this study show that environmental chemicals cause
congenital abnormalities?
Yes, the hypothesis test shows that environmental chemicals cause the genetic abnormality.This study does not address what causes the genetic abnormality. No, the hypothesis test shows that environmental chemicals do not cause the genetic abnormality.
Solution:
Ho:p=0.05
Ha:p>0.05
H0: p = 0.05 vs. Ha: p > 0.05
np=366*0.05=18.3>15
n(1-p)=366*(1-0.05)= 347.7>15
The 15 successes and failures condition is met.
The sample was randomly chosen.
Solution-c:
In ti 83 calsulcator
Go to STAT>TESTS>1-PropZTest
to get z and p value
p value=0.032
The p-value is the chance of observing 26 or more children with genetic abnormalities in a random sample of 366 children, if the true proportion of children with genetic abnormalities is 5%.
(e) What is the conclusion of the hypothesis test, for α = 0.05?
p=0.032
alpha=0.05
p<0.05
Reject Ho
Reject H0. There is sufficient evidence that more than 5% of this nation's children have genetic abnormalities.
(f) Do this study show that environmental chemicals cause
congenital abnormalities?
his study does not address what causes the genetic abnormality.