A scientist is weighing each of 30 fishes. Their mean weight worked out is 30 gm and standard deviation of 2 gm. Later, it was found that the measuring scale was misaligned and always under reported every fish weight by 2 gm. The correct mean and standard deviation (in gm) of fishes are respectively.

A scientist is weighing each of 30 fishes. Their mean weight worked out is 30 gm and standard deviation of 2 gm. Later, it was found that the measuring scale was misaligned and always under reported every fish weight by 2 gm. The correct mean and standard deviation (in gm) of fishes are respectively.

  1. A

    32, 4

  2. B

    28, 2

  3. C

    28, 4

  4. D

    32, 2

    Register to Get Free Mock Test and Study Material

    +91

    Verify OTP Code (required)

    I agree to the terms and conditions and privacy policy.

    Solution:

    Let x1,x2,,x30 be actual weights of 30 fishes and y1,y2,,y30 be the weights of fishes taken from misaligned increasing scale. Then,

        yi=xi+2; i=1,2,,30

    Y¯=X¯+2 and σY=σX  Standard deviation is in-  dependent of change of origin 

     30=X¯+2 and σY=2

     X¯=28 and σY=2

    Chat on WhatsApp Call Infinity Learn

      Register to Get Free Mock Test and Study Material

      +91

      Verify OTP Code (required)

      I agree to the terms and conditions and privacy policy.