ANSWER FOR THE TIMEPOINT ASSIGNED TO YOU (6 MONTHS) In an experiment by JC de Ru

Question

ANSWER FOR THE TIMEPOINT ASSIGNED TO YOU (6 MONTHS)

In an experiment by JC de Ruyter et al. (NEJM, 2012), children were assigned to drink either a sugar-sweetened drink or a sugar-free drink (in which the sweetener was sucralose) each day for 18 months. The investigators evaluated compliance with the drinking regimen by collecting urine from participating children at 6 months, 12 months, and 18 months into the study, and measuring urinary sucralose concentration in mg/liter. The measurements are summarized in the boxplots below.

The black dots in these boxplots represent means. (Yes…they have mixed a statistic obtained by arithmetic with statistics based on order, which some would consider criminal.) Otherwise, these boxplots conform exactly to what we have learned about boxplots. Any parts of a box or lower whisker that you can’t see are all scrunched at the minimum value.

For the SUGAR-FREE GROUP at the timepoint 6 MONTHS, use the boxplot to find the 5-number summary for the distribution of urinary sucralose. (You should label each of the five numbers in your five-number summary.)

Label

MIN

Q1

MED

Q3

MAX

Value

For the SUGAR-FREE GROUP at the timepoint OF 6 MONTHS, what is the shape of the distribution of urinary sucralose? In one sentence, say how the location of the black dot that represents the mean is consistent with your answer.

For the SUGAR-SWEETENED GROUP at the timepoint OF 6 MONTHS, use the boxplot to find the 5-number summary for the distribution of urinary sucralose. This is not a trick question; keep in mind that urinary sucralose cannot be below 0. (If you read the caption, you will see that the investigators used 0.01 mg/liter as the minimum possible value for each participant.) (Label the five numbers in your five-number summary.)

Label

Value

Label

MIN

Q1

MED

Q3

MAX

Value

24- HL 18 5 14- u 12 6 Months 12 Months 18 Months Figure 2. Urinary Sucralose Concentrations. The sucralose concentration was determined in spot urine samples by means of liquid chromatography with mass spectrometry.21 Samples wene obtained from randomy selected children who completed the study. We assigned a value of 0.01 to samples below the detection limit of 0.02 mg per liter. The upper and lower ends of the boxes indicate the 25th and 75th quartiles, the black dots means, the horizontal lines within the boxes me- dians, the upper whisker the maximum value, and the lower whisker the minimum value. Values for the sugar-free group are based on samples

Explanation / Answer

SUGAR-FREE GROUP (6 MONTHS TIME POINT)

For the SUGAR-FREE GROUP, the shape of the distribution is right-skewed. For a right-skewed distribution mean > median> mode,

Now as the black dot ( corresponding to the mean ) is greater than the median, hence the location of the mean is consistent with our answer.

SUGAR-SWEETENED GROUP (6 MONTHS TIME POINT)

LABEL MIN Q1 MED Q3 MAX VALUE 0.01 3 6 9.5 19

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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