Answer:
Step-by-step explanation:
Total number of kindergarten children in that region that were tested is 160
It is generally believed that nearsightedness affects about 12% of children in a certain region. Therefore,
The expected number of kindergarten children expected to be nearsighted is
12/100 × 160 = 19
Probability of success, p = 0.12
Probability of failure, q = 1 - p = 1 - 0.12 = 0.88
Standard deviation = √npq = √(160 × 0.12 × 0.88) = 4.11
