Question

3.4 Assess Your Understanding

Applying the Concepts #5

Applying the Concepts NW 5. Birth Weights Babies born after a gestation period of 32-35 weeks have a mean weight of 2600 grams and a standard deviation of 660 grams. Babies born after a gestation period of 40 weeks have a mean weight of 3500 grams and a standard deviation of 470 grams. Suppose a 34-week gestation period baby weighs 2400 grams and a 40-week gestation period baby weighs 3300 grams. What is the z-score for the 34-week gestation period baby? What is the z-score for the 40-week gestation period baby? Which baby weighs less relative to the gestation period?

Answer 1

Answer :

given data :-

mean weight = 3500 grams

mean weight = 3500 grams

mean weight = 3500 grams

standard deviation = 660

babies born after a period of 32-35 weeks

Babies born after gestation period of 40 weeks

have an mean weight = 3500 grams

$\mu$ =3500

mean weight = 3500 grams

standard deviation = 470 grams

  $\sigma$ = 470

a 40 week gestation period baby weighs = 3300 grams

Z score for X =3300 grams

we know that

Z = X- $\mu$/ $\sigma$

= 3300-3500/470

= -200/470

Z = -0.4255

34 week gestation period baby weighs

X = 2400 grams

have an mean weight = 3500 grams

standard deviation = 660

Z = X- $\mu$/ $\sigma$

Z= 2400-2600/660

Z= -200/660

Z= -0.3030

$\therefore$ THE 40 WEEKS BABY WEIGHS LESS RELATIVE TO GESTATION PERIOD.