Answer
a) Normal disribution.
b)4.5
c)0.5
Work Step by Step
a) The distribution is basically a normal distribution. Also, because there are only 3 digits, sometime it can be a bit distort compared to a normal distribution.
b)The possible digits are from 0 until 9, therefore the mean, which is the sum of all possibilities, divided by the number of possibilites, is: $\frac{0+1+2+3+4+5+6+7+8+9}{10}=4.5.$ The mean of all sample means is 4.5 too, therefore this is the value the sample means target.
c) The proportions of odd numbers is the number of odd digits divided by the number of all digits. $\frac{5}{10}=0.5$ Hence, the mean of all sample proportions is 0.5.