Question 1076183
mean is 383*.75=287.25
variance is np(1-p)=71.81=mean*.25
sd= sqrt (V)=8.47
continuity correction factor
z=(299.5-287.25)/71.81=0.1706. and probability z>300=0.4322
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between 260 and 300 
z=(259.5-287.25)/8.47=-3.34
z=(300.5-287.25)/8.47=1.56
0.9406
It is a little more than 0.50+0.4322 because of the continuity correction factor.