A growth chart is a plot of the percentiles of growth measurements, such as weig

Question

A growth chart is a plot of the percentiles of growth measurements, such as weight and height, for a population of infants or children. It is used by pediatricians to assess a child's growth over time. The Centers for Disease Control and Prevention (CDC) is a U.S. agency devoted to the protection and promotion of public health. Through one of its units, the National Center for Health Statistics (NCHS), the CDC has developed growth charts for clinical use by health professionals. The most recent charts were published in 2000. The 2000 CDC growth charts were developed using a reference population of infants. A pediatrician looks up one of the charts and finds that the 90th percentile for weights of baby girls at 18-1/2 months is 29.9 pounds. This means that ______ of the 18-1/2-month-old baby girls in the reference population weigh 29.9 pounds or less, and _______ of these baby girls weigh 29.9 pounds or more. The 2000 CDC growth charts use a reference population of both breast-fed and formula-fed infants. It has been observed that breast-fed babies tend to gain weight more rapidly than formula-fed babies in the first 2 to 3 months of their lives, but they tend to weigh less than formula-fed babies from 6 to 12 months. Sarah is a healthy baby who was exclusively breast-fed for her first 12 months. Which of the following is most likely a description of her weights (at 3, 6, 9, and 12 months of age) as percentiles of the CDC growth chart reference population? 30th percentile at 3 months: 30th percentile at 6 months: 30th percentile at 9 months: 30th percentile at 12 months 75th percentile at 3 months: 85th percentile at 6 months: 95th percentile at 9 months: 95th percentile at 12 months 10th percentile at 3 months: 40th percentile at 6 months: 75th percentile at 9 months: 95th percentile at 12 months 65th percentile at 3 months: 35th percentile at 6 months: 30th percentile at 9 months: 20th percentile at 12 months The following are weights (in pounds) for a sample of 11 baby boys at the age of 15 months: The 85th percentile for these sample data is _______ pounds. In the sample data, _____ out of 11 observations are less than or equal to the 85th percentile, and _______ out of 11 observations are greater than or equal to this value. For any data set, the first quartile is the ______ percentile, the second quartile is the _____ percentile and the _______, and the third quartile is the _______ percentile. In the prior sample data, the first quartile is ______ pounds, and the third quartile is ______. Therefore, the interquartile range is ________.

Explanation / Answer

This means that 90% of the 18-1/2 month-old baby girls in the reference popuation wiegh 29.9 pounds or less, and 10% of these baby girls weigh 29.9 or more.
Correct Answer: option (C)

The 85th percenitle of these sample data is
85(11+1)/100= 10.2th term
= 10th term + 0.2(11th-10th) terms
= 26.6 + 0.2(27.9-26.6) = 26.86 pounds
In this sample data, 10 out of 11 observatin are < = 85th percentile, and 1 out of 11 observation are > = to this value.

For any data set, the first quatile is 25% percentaile, the seocnd quartile is the 50th percentile and Q2 or median, and the thirds quartile is the 75th percentile.

From sample Q1 = (N+1)/4 = 12/4 = 3rd term = 22.2
Q3 = 3(N+1)/4 = 3*12/4 = 9rd term = 25.1
Interquartile Range = Q3-Q1 = 25.1 - 22.2 =2.9

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.