A group of eight individuals with high cholesterol levels were given a new drug that was designed to lower cholesterol levels. Cholesterol levels, in mg/dL, were measured before and after treatment for each individual, with the following results:
a. Can you conclude that the mean cholesterol level after treatment is less than the mean before treatment?
b. Can you conclude that the reduction in mean cholesterol level after treatment is greater than
Topic: Weathering Takes longer in dry environments; accelerates in wet environments Types of Weathering: 1) Mechanical/Physical: breakup of rock into smaller rocks a. Frost Wedging: involves expansion and contraction of water in rock crack due to freezing and thawing b. Frost heaving: Up thrust of sediment or soil due to the freezing of wet soil beneath c. Salt crystal growth: involves buildup of salts on rock surfaces through evaporation. Salt weakens the rock, making it vulnerable d. Exfoliation: sheets of rock flake away due to seasonal temperature changes or by the expansion of rock due to unloading 2) Chemical: dissolves the rock a. Oxidation: oxygen chemically combines with metallic iron to form iron oxides, losses in elections. (color changes) b. Carbonation: caused by rain water that has absorbed atmospheric carbon dioxide c. Acid rain: human cause. Precipitation of strong mineral acids, primarily sulfur dioxide and nitrogen oxides, originating in factories. 3) Differential: two different rock types weather at different rates Mass wasting: movement of rock, sediment and soil downslope due to force of gravity Happens when downward force of gravity overcomes the resisting force of the slope’s material shearing strength Colluvium – unconsolidated sediment that accumulates at the base of slope Types of mass wasting: 1) Rock fall 2) Soil creep 3) Landslides 4) Slump 5) Earth flow 6) Mudflow 7) Avalanches