Show that each of the following families of distributions is an exponential family, as defined in Exercise 23:
a. The family of Bernoulli distributions with an unknown value of the parameter p
b. The family of Poisson distributions with an unknown mean
c. The family of negative binomial distributions for which the value of r is known and the value of p is unknown
d. The family of normal distributions with an unknown mean and a known variance
e. The family of normal distributions with an unknown variance and a known mean
f. The family of gamma distributions for which the value of α is unknown and the value of β is known
g. The family of gamma distributions for which the value of α is known and the value of β is unknown
h. The family of beta distributions for which the value of α is unknown and the value of β is known
i. The family of beta distributions for which the value of α is known and the value of β is unknown