Home
Class 9
MATHS
The mean of 100 items was found to be 64...

The mean of 100 items was found to be 64. later on, it was discovered that two itens were misread as 26 and 9 instead of 36 and 90 respectively. Find the correct mean.

A

65.31

B

64.86

C

64.91

D

64.61

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • STATISTICS

    MODERN PUBLICATION|Exercise EXERCISE|239 Videos

  • QUADRILATERALS

    MODERN PUBLICATION|Exercise EXERCISE|133 Videos

  • SURFACE AREAS AND VOLUMES

    MODERN PUBLICATION|Exercise EXERCISE|228 Videos

Similar Questions

Explore conceptually related problems

The mean of 200 items was 50. later on, it was discovered that the two items were misread as 92 nd 8 instead of 192 and 88, find the correct mean.

The mean of marks scored by 100 students was found to be 40, later on, it was discovered that a score of 53 was misread as 83. find the correct mean.

Mean of 50 observations was found to be 80.4. but later on, it was discovered that 96 was misread as 69 at one place. Find the corect mean.

The mean of 40 numbers was found to be 35. Later on, it was detecte that a number 56 was misread as 36. find the correct mean of the given numbers.

The mean and standard deviation of a group of 100 observations were found to be 20 and 3, respectively. Later on it was found that three observations were incorrect, which were recorded as 21, 21 and 18. Find the mean and standard deviation if the incorrect observations are omitted.

In the chemical analysis of a rock the mass ratio of two radioactive isotopes is found to be 100:1. The mean lives of the two isotopes are 4xx10^9 years and 2xx10^9 years, respectively. If it is assumed that at the time of formation the atoms of both the isotopes were in equal propotional, calculate the age of the rock. Ratio of the atomic weights of the two isotopes is 1.02:1.

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

The mean and standard deviation of 100 observations were calculated as 40 and 5.1 respectively by a student who took by mistake 50 instead of 40 for one observation. What are the correct mean and standard deviation ?

MODERN PUBLICATION-STATISTICS-EXERCISE
  1. If the mean of the observations : x, x + 3, x + 5, x + 7, x + 10 is 9,...

    Text Solution

    |

  2. Let barx be the mean of x1,x2,……,xn and bary the mean of y1,y2……,yn ba...

    Text Solution

    |

  3. The mean of 100 items was found to be 64. later on, it was discovered ...

    Text Solution

    |

  4. The mean of the following table is 8 The value of p is

    Text Solution

    |

  5. The median of the number 84,78,54,45,68,22,34,45,39,54 is

    Text Solution

    |

  6. Mode of the data 15, 14, 19, 20, 14, 15, 1 6, 14, 15, 18, 14, 19, 15, ...

    Text Solution

    |

  7. In a histogram, each class rectangle is constructed with base as

    Text Solution

    |

  8. A histogram is a pictorail representation of the frequency data in whi...

    Text Solution

    |

  9. In the less than type of ogive the comulative frequency is plotted aga...

    Text Solution

    |

  10. In a histogram the area of each rectangle is proportional to

    Text Solution

    |

  11. In a frequency distribution, gives are graphical represented of

    Text Solution

    |

  12. The class mark of the class 90-120 is

    Text Solution

    |

  13. The range of the data: 27,18,20,16,6,17,15,12,30,32,10,19,8,11,20 is

    Text Solution

    |

  14. In a frequency distribution, the mid value of a class is 10 and width ...

    Text Solution

    |

  15. The width of each of five continuous classes in a frequency distibutio...

    Text Solution

    |

  16. Let m be the mid-point and l be the upper class limit of a class in a ...

    Text Solution

    |

  17. The class marks of a frequency distribution are given as follows : 15,...

    Text Solution

    |

  18. In the class intervals 10-20, 20-30, the number 20 is included in.

    Text Solution

    |

  19. A grouped frequency table with class intervals of equal sizes using 25...

    Text Solution

    |

  20. A grouped frequency distribution table with classes of equal sizes usi...

    Text Solution

    |