How do you calculate the expected value for this goodness of fit test? The Frequency is the observed value how do you compute the expected value in this problem from that

The results of a recent national survey reported that 70% of Americans recycle at least some of the time. As part of their final project in statistics class, Nayla and Roberto survey 5 random students on campus and ask them if they recycle at least some of the time. They then repeat this experiment 1000 times. The results of their research are shown below. X (number who recycle out of 5) 0 1 2 3 4 5 Frequency 2 25 140 305 357 171 Is there evidence to support the belief that the random variable X, the number of students out of 5 who recycle at least some of the time, is a binomial random variable with p =0.7 at the a = 0.05 level