Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Let x = red blood cell (RBC) count in millions per cubic millimeter of whole blo

ID: 2946386 • Letter: L

Question

Let x = red blood cell (RBC) count in millions per cubic millimeter of whole blood. For healthy females, x has an approximately normal distribution with mean ? = 5.1 and standard deviation ? = 0.3.

(a) Convert the x interval, 4.5 < x, to a z interval. (Round your answer to two decimal places.)
< z

(b) Convert the x interval, x < 4.2, to a z interval. (Round your answer to two decimal places.)
z <  

(c) Convert the x interval, 4.0 < x < 5.5, to a z interval. (Round your answers to two decimal places.)
< z <  

(d) Convert the z interval, z < ?1.44, to an x interval. (Round your answer to one decimal place.)
x <  

(e) Convert the z interval, 1.28 < z, to an x interval. (Round your answer to one decimal place.)
< x

(f) Convert the z interval, ?2.25 < z < ?1.00, to an x interval. (Round your answers to one decimal place.)
< x <  

(g) If a female had an RBC count of 5.9 or higher, would that be considered unusually high? Explain using z values.

Yes. A z score of 2.67 implies that this RBC is unusually high.No. A z score of ?2.67 implies that this RBC is unusually low.    No. A z score of 2.67 implies that this RBC is normal.

The Standard Normal Distribution = 0, ? = 1) 3 2 68% of area 95% of area 99.7% of area

Explanation / Answer

a) x>4.5

z >(4.5-5.1)/0.3

z>-2

b) x<4.2

z <(4.2-5.1)/0.3

z<-3

c) 4.0 < x < 5.5

= ((4.0-5.1)/0.2<z<(5.5-5.1)/0.3

= -3.67<z<1.33

d) z < ?1.44

x = -1.44*0.3+5.1

x<4.67