Answer:
<u>Part A</u>
<u>μ of the reading speed of sixth-grade students = 125 words</u>
<u>σ of the reading speed of sixth-grade students = 24 words</u>
<u>Part B</u>
<u>The probability that a randomly selected sixth-grade student reads less than 100 words per minute is 14.92%</u>
<u>Part C</u>
<u>The probability that a randomly selected sixth-grade student reads more than 140 words per minute is 26.43% </u>
Step-by-step explanation:
Part A:
μ of the reading speed of sixth-grade students = 125 words
σ of the reading speed of sixth-grade students = 24 words
Part B:
1. Let's find the z-score for a randomly selected sixth-grade student that reads less than 100 words per minute:
z-score = (100 - 125)/24
z-score = -25/24
z-score = -1.04
2. Now, let's find out the probability that a randomly selected sixth-grade student that reads less than 100 words per minute, using the z-table:
P (-1.04) = 0.1492
<u>This means that the probability that a randomly selected sixth-grade student that reads less than 100 words per minute is 14.92%</u>
Part C.
1. Let's find the z-score for a randomly selected sixth-grade student that reads more than 140 words per minute:
z-score = (140 - 125)/24
z-score = 15/24
z-score = 0.63
2. Now, let's find out the probability that a randomly selected sixth-grade student that reads more than 140 words per minute, using the z-table:
P (0.63) = 0.7357
But we're being asked for a randomly selected student that reads more than 140 words, then:
1 - P(0.63) = 1 - 0.7357 = 0.2643
<u>This means that the probability that a randomly selected sixth-grade student that reads more than 140 words per minute is 26.43%</u>
