COVID-19 pandemic growth rate. The COVID-19 pandemic growth rate distribution in different countries between March 9 and March 15, 2020 is shown in the following table. A country is to be randomly selected from this population. Growth Rate (% per day) 5 15 25 35 45 55 80 90 Country Proportion .16 .19 .25 .12 .13 .10 .05 .01 Source: A. Weber, F. Iannelli, and S. Goncalves, “Trend Analysis of the Covid-19 Pandemic in China and the Rest of the World,” https://www.medrxiv. org, March 23, 2020.

a. Can the relative frequency distribution in the table be interpreted as a probability distribution? Explain. CRASH M04_MCCL3396_14_GE_C04.indd 219 29/09/2021 14:00 220 CHAPTER 4 ● Random Variables and Probability Distributions

b. Graph the probability distribution.

c. What is the probability that the randomly selected country has the growth rate of more than 25% per day? More than 45% per day? Less than 15% per day?

d. What is the probability that the randomly selected country’s growth rate will be 35% or 45% per day?