a.
The sample is consisted of 919 peas and 720 have red flowers
If we assuma a 3/4 probavility that a pea will have a red flower, according to a binomial distribution (that is, which assumes only to possible outcomes: red and not red), the standard deviation must be given by:
[tex]\begin{gathered} \sigma=\sqrt[]{np(1-p)} \\ \sigma=\sqrt[]{919\cdot\frac{3}{4}(1-\frac{3}{4})} \\ \sigma\approx\sqrt[]{172} \\ \sigma\approx13.1268 \end{gathered}[/tex]Then, the Z score of 720 with a expected value of 689;25 and a standard deviation of 13.1268 is given by:
[tex]Z=\frac{720-689.25}{13.1268}\approx2.3425[/tex]Using a normal approximation, according to a normal distribution table, we conclude that the probability of getting 720 or more peas with red flowers is given by 0.0096 = 0.96%
b.
Usually, when a