The ages of the 200 individuals in a supplied health data set are grouped below.
Age a (years)10≤a<2020≤a<3030≤a<4040≤a<5050≤a<6060≤a<7070≤a<8080≤a<90Frequency3226392620231519\begin{array}{c|cccccccc}\text{Age }a\text{ (years)}&10\leq a<20&20\leq a<30&30\leq a<40&40\leq a<50&50\leq a<60&60\leq a<70&70\leq a<80&80\leq a<90\\\hline\text{Frequency}&32&26&39&26&20&23&15&19\end{array}Age a (years)Frequency10≤a<203220≤a<302630≤a<403940≤a<502650≤a<602060≤a<702370≤a<801580≤a<9019
State the modal class.
Find the probability that an individual selected at random from the data set is aged at least 70.
105 exam-style questions on WJEC A Level Maths 2.2 Data presentation and interpretation, covering 2.2.1 Data presentation and interpretation, 2.2.2 Data presentation and interpretation, 2.2.3 Data presentation and interpretation, 2.2.4 Data presentation and interpretation, 2.2.5 Data presentation and interpretation, 2.2.6 Data presentation and interpretation, 2.2.7 Data presentation and interpretation, 2.2.8 Data presentation and interpretation, and 2.2 Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.