SOLUTION: 1) The probability that a radish seed will germinate is 0.7. Estimate the probability that of 140 randomly selected seeds, exactly 100 will germinate. Using normal distribution

It is a standard and typical Binomial distribution probability problem
with the number of trials n= 140, number if successful trials k= 100 and
the individual probability of success p= 0.7 for each single trial.


Since the number of trials/succesful trials is great (greater than 30),
a good style is to use the normal distribuition approximation.


This normal approximation has the mean value m = n*p = 140*0.7 = 98
and the standard deviation SD =  =  = 5.422.


So, the probability under the question is the area under the specified normal 
curve between the marks 99.5 and 100.5 (using the continuity correction factor)

    p - normalcfd (99.5,100.5, 98, 5.422) = 0.0687  (rounded).


You may use your calculator or an online free of charge calculator

https://onlinestatbook.com/2/calculators/normal_dist.html