the ages of rocks can be determined using the isotope 135cs, which undergoes beta decay with a half-life of 2.3×106 y. a rock sample contains a ratio of 135ba to 135cs of 0.15. given that 135ba is a stable product of the beta decay of 135cs, and assuming there was originally no 135ba present in the rocks, calculate the age of the rock sample.

Heights of men on a baseball team have a bell-shaped distribution with a mean of 177 cm and a standard deviation of 6 cm. using the empirical rule, what is the approximate percentage of the men between the following values? a. 159 cm and 195 cm b. 165 cm and 189 cm a. 89% of the men are between 159 cm and 195 cm. (round to one decimal place as needed.) b. 89% of the men are between 165 cm and 189 cm. (round to one decimal place as needed.)

These two squirrels live in the same ecosystem. what type of interaction do the images represent? a. direct competition b. mutualism c. interference competition d. symbiotic e. indirect competition

Which group of college students is typically offered scholarship? a. freshmen, sophomores, and juniors. b. biology, english, and engineering majors. c. hard workers, part-time students, and out of state students. d. first time freshmen, current students, and transfer students.