gaokao 2019 Q14

gaokao · China · national-II-arts Measures of Location and Spread
14. China's high-speed rail development is rapid and technologically advanced. According to statistics, among high-speed trains stopping at a certain station, 10 trains have an on-time rate of 0.97, 20 trains have an on-time rate of 0.98, and 10 trains have an on-time rate of 0.99. The estimated value of the average on-time rate for all trains stopping at this station is $\_\_\_\_$ .
$\frac { 121 } { 3 }$
14. China's high-speed rail development is rapid and technologically advanced. According to statistics, among high-speed trains stopping at a certain station, 10 trains have an on-time rate of 0.97, 20 trains have an on-time rate of 0.98, and 10 trains have an on-time rate of 0.99. The estimated value of the average on-time rate for all trains stopping at this station is $\_\_\_\_$ .