To assess the health of a stream for supporting aquatic life, dissolved oxygen was measured in 15 samples taken downstream from a sewerage treatment plant. Current research asserts that the mean dissolved oxygen level must be at least 5.0 parts per million (ppm) for fish to survive. The sample mean was 4.65, with standard deviation 0.35. Assume dissolved oxygen is normally distributed. Enter your responses to all parts in the text box below. a) Choose the correct hypotheses to test if the dissolved oxygen downstream from the sewerage plant is significantly less than 5.0 ppm. Write only the letter corresponding to the answer.

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