(a) Approximately what proportion of healthy children have left atrial diameters less than 24 mm? (b) Approximately what proportion of healthy children have left atrial diameters greater than 32 mm? (c) Approximately what proportion of healthy children have left atrial diameters between 25 and 30 mm? (d) For healthy children, what is the value for which only about 20% have a larger left atrial diameter? mm

A researcher claims that at least 10% of all football helmets have manufacturing flaws that could potentially cause injury to the wearer. A sample of 200 helmets revealed that 16 helmets contained such defects. Does this finding support the researcher's claim? Use a = 0.03. Find the P-value. The proportion of football helmets with flaws The P-value is i ✓ 10%. . Round your answer to four decimal places (e.g. 12.3456).

Q5. Borer et al. [1980], study 45 individuals after an acute myocardial infarction (heart attack). They measure the ejection fraction (EF); the EF is the percent of the blood pumped from the left ventricle (the pumping chamber of the heart) during a heart beat. A low EF indicates damaged or dead heart muscle (myocardium). During follow-up four patients died. Dividing EF into low ( 35% 4. 9. 0. 32 Is there reason to suspect, at a 0.05 significance level, that death is more likely in the low EF group? Use a one-sided p-value for your answer, since biological plausibility (and prior literature) indicates low EF is a risk factor for mortality.

d. There is a 30% chance that X is above what value? X= (Type an integer or decimal rounded to two decimal places as needed.)

C?

Can balloons hold more air or more water before bursting? A student purchased a large bag of 12-inch balloons. He randomly selected 10 balloons from the bag and then randomly assigned half of them to be filled with air until bursting and the other half to be filled with water until bursting. He used devices to measure the amount of air and water was dispensed until the balloons burst. Here are the data

Statistics Question

Is it true that z values have no units of measurements?

Researchers investigated the effect of weed-killing herbicides on house pets. They examined 822 dogs from homes where herbicides were used regularly, diagnosing malignant lymphoma in 475 of them. Of the 125 dogs from homes where no herbicides were used, only 15 were found to have lymphoma. Complete parts a through c. a) What is the standard error of the difference in the two proportions? (Round to five decimal places as needed.)

A study at Harvard found that 44% of their students binge drink.  You are at Princeton doing a similar study.  How many people do you need to interview to get your interval width down to 10 percentage points?  For a 95% CI, what is that sample size?