<li>586/24</li>
</ol>
<p>Birth Weights: An obstetrician maintains that preterm babies (gestation period less than 37 weeks) have a higher variability in birth weight than do full-term babies (gestation period 37-41 weeks). According to the National Vital Statistics Report, Vol. 48, No.3, the birth weights of full-term babies are normally distributed, with standard deviation 505.6 grams. A random sample of 41 preterm babies results in a standard deviation equal to 840 grams. Test the researcher’s claim that the variability in the birth weight of preterm babies is more than the variability in birth weight of full-term babies, at the alpha=0.01 level of significance.</p>
<p>Can somone help me? How do I write the null hypothesis and the alternative hypothesis?</p>
<p>Ho: Variability of birthweight of preterm babies and birthweight of full-term babies is the same</p>
<p>Ha: Variability of preterm babies is more than full term babies</p>
<p>Thank you so much. Which equation do I use? I only know which one to use if they’re asking to compare the mean or the percentage. What about the standard deviation? Which equation do I use to compare this?</p>
<p>How can I calculate the sample standard deviation?</p>
<p>I am using the formula chi-square = ((n-1)s^2)/sigma^2 to calculate the test statistics. What is “s” in this case?</p>
<p>Someone please tell me how to calculate the test statistic for this problem. I have everything except “s” in the formula. How can I get it?</p>
<p>Wow. It took me one hour to figure out that “s” was given in the problem. 840!!!</p>