In a survey of women in a certain country (ages 20 -29), the mean height was 64.

Question

In a survey of women in a certain country (ages 20 -29), the mean height was 64.2 inches with a standard deviation of 2.69 inches. Answer the following questions about the specified normal distribution. (a) What height represents the 95th percentile? (b) What height represents the first quartile? Click to view page 1 of the table. Click to view page 2 of the table. (a) The height that represents the 95th percentile is inches. (Round to two decimal places as needed.) (b) The height that represents the first quartile is (Round to two decimal places as needed.) inches.

Explanation / Answer

Mean is 64.2 and s is 2.69

a) z for 0.95 from normal distribution table has a z value of 1.65, thus answer is mean+z*s=64.2+2.69*1.65= 68.64

b) z for 0.25 is actually negative of z for 1-0.25 i.e 0.75, form normal table it is -0.68

thus answer is 64.2-0.68*2.69=62.37

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

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