The term "El Nino" refers to the warming of the central and eastern tropical Pacific waters that occurs every 3 to 7 years and typically lasts from 9 to 12 months. The 1997-1998 El Nino, the strongest ever recorded, affected climate patterns worldwide. Its effect, combined with an increasing trend in annual global temperatures, made 1998 the warmest year in the 20th century.

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uppose you are a climatologist. You conduct a hypothesis test to determine whether the global mean temperature in the current year is lower than the global mean temperature in 1998. Assume that the global mean temperature in 1998 was 14.3 degrees Celsius (the population mean). You obtain a preliminary sample of temperatures from recording stations worldwide, which yields a sample mean of M = 15.1 degrees Celsius.

Let denote the global mean temperature in the current year. Formulate your null and alternative hypotheses by selecting the appropriate values in the blue dropdown menus that follow.

H: _____. ________. _________

H: _______ _______. ________

• The test you conduct isa. two-tailed or a one-tailed

test.