The following is the record of goals scored by team A in a football session:

No. of goals scored | 0 | 1 | 2 | 3 | 4 |

No. of matches | 1 | 9 | 7 | 5 | 3 |

For the team B, mean number of goals scored per match was 2 with a standard deviation 1.25 goals. Find which team may be considered more consistent?

Asked by Abhisek | 11 months ago | 97

\( \displaystyle\sum_{i=1}^{15} f_i x_i=\dfrac{50}{25}=2\)

Thus, the mean of both the teams is same

Variance = \( \dfrac{1}{N^2}[ N\displaystyle\sum f_i x_i^2-(\displaystyle\sum f_i x_i)^2] \)

= \( \dfrac{1}{25^2}[(25\times 30)-2500]\)

= \( \dfrac{750}{625}=1.2\)

Standard deviation σ = \( \sqrt{Variance}\)

= \( \sqrt{1.2}\) = 1.09

The standard deviation of team B is 1.25 goals. The average number of goals scored by both the teams is same i.e., 2. Therefore, the team with lower standard

deviation will be more consistent. Thus, team A is more consistent than team B.

Find the mean deviation from the mean and from a median of the following distribution:

Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |

No. of students | 5 | 8 | 15 | 16 | 6 |

The age distribution of 100 life-insurance policy holders is as follows

Age (on nearest birthday) | 17-19.5 | 20-25.5 | 26-35.5 | 36-40.5 | 41-50.5 | 51-55.5 | 56-60.5 | 61-70.5 |

No. of persons | 5 | 16 | 12 | 26 | 14 | 12 | 6 | 5 |

Compute mean deviation from mean of the following distribution:

Marks | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 | 80-90 |

No. of students | 8 | 10 | 15 | 25 | 20 | 18 | 9 | 5 |

Find the mean deviation from the mean for the following data:

Classes | 95-105 | 105-115 | 115-125 | 125-135 | 135-145 | 145-155 |

Frequencies | 9 | 13 | 16 | 26 | 30 | 12 |

Find the mean deviation from the mean for the following data:

Classes | 0-100 | 100-200 | 200-300 | 300-400 | 400-500 | 500-600 | 600-700 | 700-800 |

Frequencies | 4 | 8 | 9 | 10 | 7 | 5 | 4 | 3 |