Question

10different things of loudness arranged in ascending oder

Answer 1

Whisper-20dB

Quiet Residence-30dB

Soft stereo in Residence-40dB

Average Speech-60dB

Cafeteria-80dB

Pneumatic Jackhammer-90dB

Loud crowd noise-100dB

Accelerating Bike-100dB

Rock concert-120dB

Jet Engine (75 ft away)-140dB

(1)Mode=100dB (since 100 is occurring the maximum no. of times, i. e. it has the highest frequency of 2)

(2)Mean=sum of observations/Total number of observations

=(20+30+40+60+80+90+100+100+120+140)/10

=770/10=10dB

(3)Median= 1/2[{n/2}th observation + {(n/2)+1}th observation], where, n=total no. of observations

So, 1/2[{10/2}th observation + {(10/2)+1}th observation]

=1/2[5th observation+6th observation]

=1/2[80+90] [Because:5th observation=80dB and 6th=90dB]

=1/2(170)

=85

Therefore, median=85dB