# A group of 894 women aged 70-79 had their height and weight measured. The mean height was 159 cm with a standard deviation of 5 cm and the mean weight was 65.9kg with a standard deviation of 12.7kg. Both sets of data are fairly normal?

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A.) Suppose you were asked for a range of typical heights and weights for this population of women. What values would you give? Explain.

B.) Which of the two measurements appears more variable? Explain.

C.) What percentage of the population is expected to be taller than 166cm?

D.) What percentage of the population is expected to weigh between 55 and 75kg?

E.) Above what weight will 85% of the population lie?

A.) Suppose you were asked for a range of typical heights and weights for this population of women. What values would you give? Explain.

B.) Which of the two measurements appears more variable? Explain.

C.) What percentage of the population is expected to be taller than 166cm?

D.) What percentage of the population is expected to weigh between 55 and 75kg?

E.) Above what weight will 85% of the population lie?

##### 1 Answer

A. Height: 145 - 174cm ; Weight: 27.8 - 104kg

B. Weight is more variable in these measures.

C. to E. see below.

#### Explanation:

The key information is the mean, the standard deviation (variation about the mean) and that the data is "normal".

A. You can pick any range about the mean that you like. The number of standard deviations from the mean reflects the percentage of the population expected to be in that range.

B. "Variability" of the data is directly measure by the standard deviation. The higher standard deviation value indicates more variability in the weight measurements.

C. Go back to the "Standard Normal Distribution Curve" (or use values from the Z-tables) to find the population value corresponding to the

D. Similar to C. - Find the "area" corresponding to the

E. This is a "left-tailed" test that could also be stated as "at what weight is 15% of the population *below* the level?" Again, use the Z-value tables to find 0.85 and the corresponding