I need help with questions in problem 3 (15, 16, 17) please 14. Compute the expe

Question

I need help with questions in problem 3 (15, 16, 17) please

14. Compute the expected frequency based on Poisson distribution for K-5 a. 2.7 b. 2.5 d. 1.9 Problem 3) Lead concentrations in the egg shells of California condors have a mean of 1.8 ppm and a standard deviation of 0.5 ppm. The contamination levels of egg shells are classified as "low" if the lead concentration is below 1.0 ppm, "moderate" if the lead concentration falls between 1.0 ppm and 2.1 ppm, and "high" the lead concentration is above 2.1. Assuming that the lead concentrations of egg shells follows a normal distribution, answer the following questions 15. What is the percentile of an egg shell with a lead concentration of 2.3 ppm? a. 82th b. 83th C. 84th d. 85th 16. What lead concentration corresponds to the 79th percentile? a. 2.2 ppm b. 2.5 ppm c. 2.6 ppm d. 2.7 ppm 17. What proportion of egg shells are predicted to fall into the "moderate" range? a. 0.55 b. 0.58 c. 0.67 d. 1.58

Explanation / Answer

P(X < A) = P(Z < (A - mean)/standard deviation)

15) P(X < 2.3) = P(Z < (2.3 - 1.8)/0.5)

= P(Z < 1)

= 0.8413

c) 84th percentile

16) P(X < A) = 0.79

P(Z < (A - 1.8)/0.5) = 0.79

(A - 1.8)/0.5 = 0.81

A = 2.2

a) 2.2ppm

17) P(moderate) = P(1 < X < 2.1)

= P(X < 2.1) - P(X < 1)

= P(Z < (2.1 - 1.8)/0.5) - P(Z < (1 - 1.8)/0.5)

= P(Z < 0.6) - P(Z < -1.6)

= 0.7257 - 0.0548

= 0.6709

c) 0.67

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---