Question

plzzzzz help me...... ​

Answer 1

AnswEr :

⠀⠀⠀⠀⠀

⠀⠀⠀$\bullet$⠀Frequency [v] = 980 kHz

⠀⠀⠀⠀⠀

$\implies\sf 980 \times 10^{3} Hz$

⠀⠀⠀⠀

⠀⠀⠀⠀⠀⠀⠀⠀Using Formula :

⠀⠀⠀⠀

$\star\: \: \boxed{\frak{ v = \dfrac{c}{\lambda}}}$

$\qquad\qquad\quad\underline{\sf{Substituting \ Values \ :}}$

⠀⠀⠀━━━━━━━━━━━━━━━━━━━━━━━━━━

⠀⠀⠀⠀⠀Now Finding wavelength : ⠀⠀⠀⠀

$\implies\sf v = \dfrac{ 3 \times 10^{8} ms^{-1}}{980 \times 10^{3}} \\\\\\\implies\sf \dfrac{3}{98} \times 10^{4} \\\\\\\implies\boxed{\frak{\purple{306 \ m}}}$

Hence, wavelength of the electromagnetic radiation is 306 m.

Answer 2

Answer:

The mean of the daily wages of 50 workers is 545.2 Rs.

Step-by-step-explanation:

We have given the frequency distribution of the daily wages of 50 workers.

We have to find the mean of the daily wages of those workers.

Now,

$\begin{gathered}\displaystyle{\begin{array}{|c|c|c|c|}\cline{1-4}\bf\:Class\:(\:Daily\:wages\:in\:Rs\:) & \bf\:Class\:mark\:(\:x_i\:) & \bf\:Frequency\:(\:f_i\:) & \bf\:x_i\:f_i\\\cline{1-4}\sf\:500\:-\:520 & \sf\:510 & \sf\:12 & \sf\:6120\\\cline{1-4}\sf\:520\:-\:540 & \sf\:530 & \sf\:14 & \sf\:7420\\\cline{1-4}\sf\:540\:-\:560 & \sf\:550 & \sf\:8 & \sf\:4400\\\cline{1-4}\sf\:560\:-\:580 & \sf\:570 & \sf\:6 & \sf\:3420\\\cline{1-4}\sf\:580\:-\:600 & \sf\:590 & \sf\:10 & \sf\:5900\\\cline{1-4}& & \sf\:N\:=\:\sum\:f_i\:=\:50 & \sf\:\sum\:x_i\:f_i\:=\:27260\\\cline{1-4}\end{array}}\end{gathered}$

Now,

$\displaystyle{\pink{\sf\:Mean\:\overline{X}\:=\:\dfrac{\sum\:x_i\:f_i}{\sum\:f_i}}\sf\:\:\:-\:-\:-\:[\:Formula\:]}$

$\displaystyle{\implies\sf\:Mean\:\overline{X}\:=\:\cancel{\dfrac{27260}{50}}}$

$\displaystyle{\implies\sf\:Mean\:\overline{X}\:=\:\cancel{\dfrac{13630}{25}}}$

$\displaystyle{\implies\sf\:Mean\:\overline{X}\:=\:\cancel{\dfrac{2726}{5}}}$

$\displaystyle{\implies\boxed{\red{\sf\:Mean\:\overline{X}\:=\:545.2\:Rs}}}$

The mean of the daily wages of 50 workers is 545.2 Rs.