A standardized exam\'s scores are normally distributed. In a recent year, the me

Question

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1506 and the standard deviation was 311. The test scores of four students selected at random are 1930, 1240, 2200, and 1380. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1930 is (Round to two decimal places as needed.) The z-score for 1240 is (Round to two decimal places as needed.) The z-score for 2200 is (Round to two decimal places as needed.) The z-score for 1380 is (Round to two decimal places as needed.) Which values, if any, are unusual? Select the correct choice below and, if necessary, fill in the answer box within your choice. A. The unusual value(s) is/are (Use a comma to separate answers as needed.) B. None of the values are unusual.

Explanation / Answer

we know that

u=1506 sigma =311

the z score for 1930    = 1930-1506/311 = 1.36

the z score for 1240    = 1240-1506/311 = -0.86

the z score for 2200    = 2200-1506/311 = 2.23

the z score for 1380    = 1380-1506/311 = -0.41

unusual scores if z lessthan -2 and greater than 2

   here unusual score is    2.23

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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