in a study of the effect of aluminum intake on the mental development of infants
ID: 3152469 • Letter: I
Question
in a study of the effect of aluminum intake on the mental development of infants, a group of 92 infants who had been born prematurely were given a special aluminum-depleted intravenous-feeding solution. At age 18 months the neurologic development of the infants was measured using the Bayley Mental Development Index. (which is similar to the IQ score with 100 being the average in the general population.) a 95% confidence interval for the mean is (93.8,102.1)
a) interpret this interval. That is, what does the interval tell us about neourologic development in the population of prematurely born infants who reveiced intravenous-feeding?
b) Does this intercal indicate that the mean IQ of the sampled population is below the general populationg average of 100?
Explanation / Answer
a)It says that there is a 95% probability that the mean of the BMD Index in the population is between (93.8,102.1).
b)The interval indicates the range with a probability.But if we see the range,100 is to the top end of the interval.
If we calculate the mean and standard deviation using the CI,
mean=97.95
standard deviation=2.18
Hence P(x>100)=P(Z>0.94)=0.1736.
Hence there is only a 17.36% chance that mean is greater than 100.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.