Advertisements
Advertisements
प्रश्न
If the mean of 1, 2, 3, …, n is `(6"n")/11`, then the value of n is
पर्याय
10
12
11
13
Advertisements
उत्तर
11
Explanation:
The mean of 1, 2, 3, …., n is `(6"n")/11`
i.e., `(1 + 2 + 3 + 4 + ... + "n")/"n" = (6"n")/11`
`(("n"("n" + 1))/2)/"n" = (6"n")/11`
`("n" + 1)/2 = (6"n")/11`
11 (n + 1) = 2 × 6n
11n + 11 = 12n
∴ n = 11
APPEARS IN
संबंधित प्रश्न
Find Q1, Q3, D8 and P67 of the following data:
| Size of Shares | 4 | 4.5 | 5 | 5.5 | 6 | 6.5 | 7 | 7.5 | 8 |
| Frequency | 10 | 18 | 22 | 25 | 40 | 15 | 10 | 8 | 7 |
Calculate GM for the following table gives the weight of 31 persons in the sample survey.
| Weight (lbs): | 130 | 135 | 140 | 145 | 146 | 148 | 149 | 150 | 157 |
| Frequency | 3 | 4 | 6 | 6 | 3 | 5 | 2 | 1 | 1 |
A man travelled by car for 3 days. He covered 480 km each day. On the first day, he drove for 10 hours at 48 km an hour. On the second day, he drove for 12 hours at 40 km an hour and for the last day he drove for 15 hours at 32 km. What is his average speed?
The best measure of central tendency is _________.
Harmonic mean is the reciprocal of _________
Median is the same as:
The mean of the values 11, 12, 13, 14 and 15 is
Harmonic mean is better than other means if the data are for
An investor buys ₹ 1,500 worth of shares in a company each month. During the first four months, he bought the shares at a price of ₹ 10, ₹ 15, ₹ 20 and ₹ 30 per share. What is the average price paid for the shares bought during these four months? Verify your result.
The sum of deviations of all observations from the arithmetic mean of a dataset is always ______.
