Caption:


Text: Step 1 Find the Z for P=0.10 using Z table or qnorm(0.1)

Z for 10th percentile = -1.282

 

Step 2 Convert from Z to height

X =  + Z 

X = 76.4 + (-1.282)(2.9) = 72.7

Conclusion 10% of 12 month old boys are shorter than 72.7 cm 90% are taller than 72.7 cm