Which statement about population parameters and point estimates is false? O A. o is the population standard deviation. It is usually unknown. B. p is the sample mean. It is used to estimate the population mean. C. sis the sample standard deviation. It is the square root of the variance. O D. nis the sample size. It is used to calculate the sample mean. SUBMIT​

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z