Answer:
There is sufficient statistical evidence to suggest that the US presidents are taller than the average American male
Step-by-step explanation:
The given parameters are;
The mean height of American Males, μ = 69.5 inches
The mean height of 43 male presidents,
= 70.78
The standard deviation, s = 2.77 inches
The number of male presidents = 43
The null hypothesis; H₀ μ = 
The alternative hypothesis; Hₐ μ ≠
The significance level, α = 0.05
The t test for the sample with unknown population standard deviation is given as follows;

Therefore, we have;

The degrees of freedom, df = n - 1 = 43 - 1 = 42
The critical 't' value = 2.0181
Therefore, given that the t test value is larger than the critical-t, we reject the null hypothesis, therefore, there is sufficient statistical evidence to suggest that the US presidents are taller than the average American male