Question

A​ gender-selection technique is designed to increase the likelihood that a baby will be a girl. In the results of the​ gender-selection technique, 933 births consisted of 470 baby girls and 463 baby boys. In analyzing these​ results, assume that boys and girls are equally likely. a. Find the probability of getting exactly 470 girls in 933 births. b. Find the probability of getting 470 or more girls in 933 births. If boys and girls are equally​ likely, is 470 girls in 933 births unusually​ high? c. Which probability is relevant for trying to determine whether the technique is​ effective: the result from part​ (a) or the result from part​ (b)? d. Based on the​ results, does it appear that the​ gender-selection technique is​ effective? a. The probability of getting exactly 470 girls in 933 births is nothing. ​(Round to four decimal places as​ needed.)

Answer 1

a)

n=	933	p=	0.5000
here mean of distribution=μ=np=		466.5
and standard deviation σ=sqrt(np(1-p))=		15.2725

probability of getting exactly 470 girls in 933 births :

probability =

P(469.5<X<470.5)

=

P(0.2<Z<0.26)=

0.6026-0.5793=

0.0233

(please try 0.0254 if this comes wrong and revert)

b)

probability =

P(X>469.5)

=

P(Z>0.2)=

1-P(Z<0.2)=

1-0.5793=

0.4207

(please try 0.4221 if this comes wrong and revert)\

c)

the result from part b)