AnswEr :-

19. a) Express 45 mm in cm and km.

→ As we KNOW that 10mm = 1cm

1mm = 1/10 cm

45mm = (1/10 × 45) = 4.5cm

1cm = 0.00001km

4.5cm = (4.5 × 0.00001) = 0.000045km

20. The heights (in cm) of 50 students of a class are given below:

Height (in cm) 156 154 155 151 157 152 153

No. of students 8 4 10 6 7 3 12

Find the median height.

→ Here,

• NUMBER of terms, n = 50
• cumulative FREQUENCY = 8, 12, 22, 28, 35, 38, 50

Median = 1/2 { (n/2th observation + n/2 + 1st observation) }

→ 1/2 { 50/2th observation + 50/2 + 1st observation) }

→ 1/2 { 25th + 26th } observation

Here, the observation greater than 26 is 28

So, the median height will be 151.

21. Gold prices on 4 consecutive Tuesdays were as under :

Week 1st 2nd 3rd 4th

Rate per 10g (in Rs) 8500 8750 9050 9250

Draw a graph to show this information.

__________________________

Note :- Refer to the attachment for the solution of this question.

__________________________