Refer to the IEEE Journal of Oceanic Engineering (Apr. 2013) study of the characteristics of subcarriers-telecommunication signals carried on top of another-for underwater acoustic communications, Exercise 4.80 (p. 213). Recall that a subcarrier can be classified as either a data subcarrier (used for data transmissions), a pilot subcarrier (used for channel estimation and synchronization), or a null subcarrier (used for direct current and guard banks transmitting no signal). In a sample of 1,024 subcarrier signals transmitted off the coast of Martha's Vineyard, 672 were determined to be data subcarriers, 256 pilot subcarriers, and 96 null subcarriers. Suppose a communications engineer who works near Martha's Vineyard believes that fewer than 70% of all subcarrier signals transmitted in the area are data subcarriers. Is there evidence to support this belief? Test using a = .05.