50% of the babies are born female. olive wants to find the probability that 20 or more of the 50 babies born today were female. we need to design a simulation. which random device can be used to best represent this situation?
a. double sided coin heads females, tails males
b. use a random generator use number 1-100, assign 1-20 as female and 21-100 as male
c. use a pair of dice. doubles for female and the rest for male
d. use a spinner with 50 parts and assign 20 parts as female and 30 parts for male

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec