CBSE Questions for Class 11 Commerce Applied Mathematics Descriptive Statistics Quiz 7 - MCQExams.com

The line graph represent the net sales rate of Apple company from the year $$2003-2013$$. Find the increase in sales rate during $$2005-2007$$.

462007_6707db8c095b480084cd02116dc07fdb.png
  • $$16,000$$ millions
  • $$8,000$$ millions
  • $$26,000$$ millions
  • $$32,000$$ millions
According to the graph above, in which year was the ratio of the number of students enrolled at School $$B$$ to the number of students enrolled at School $$A$$ the greatest?

498743.png
  • $$1990$$
  • $$1991$$
  • $$1992$$
  • $$1993$$
  • $$1994$$
The mean of a finite set X of numbers is $$14$$, the median of this set of numbers is $$12$$, and the standard deviation is $$1.8$$. A new set Y is formed by multiplying each member of the set S by $$3$$. Determine the correct statements w.r.t. set Y:
I. The mean of the numbers is set Y is $$42$$
II. The median of the numbers in set Y is $$36$$
III. The standard deviation of the numbers is set Y is $$5.4$$
  • I only
  • II only
  • I and II only
  • I and III only
  • I, II, and III
How many watches were sold in all 5 months?
508238_7571a4b806244c1cb58a25ffd62354fc.png
  • 160
  • 180
  • 175
  • 170
Which year did the same number of boys and girls attend the conference?
537598.PNG
  • 1995
  • 1996
  • 1997
  • 1998
  • None
Grades for the test on proofs did not go as well as the teacher had hoped. The mean grade was 68, the median grade was 64, and the standard deviation wasThe teacher curves the score by raising each score by a total of 7 points. Which of the following statements is true?
I. The new mean is 75.
II. The new median is 71.
III. The new standard deviation is 7.
  • I only
  • III only
  • I and II only
  • I, II, and III
  • None of the statements are true
The figure above shows the cost of joining and buying music from a music subscription service. What does the y-intercept of the line most likely represent?
493896_6d87b5a07529468395b41124aa20c2c3.png
  • The cost per song
  • The cost to join the service
  • The cost of buying 20 songs
  • The cost of 20 subscriptions to the service
In a final buzzer round of a competition, contestants were asked to name as many states that begin with the letter $$K$$, by pressing the buzzer as early as possible., The bar graph shows the number of states the contestants were able to name. Find the number of contestants who participated in final buzzer round.

478494_02b0860a5a5a459db8769f2c1cd7ef8d.png
  • $$6$$
  • $$8$$
  • $$14$$
  • $$20$$
A random variable $$X$$ has the probability distribution given below. Its variance is 
X12345
P(X=x)k2k3k2kk
  • $$\dfrac{16}{3}$$
  • $$\dfrac{4}{3}$$
  • $$\dfrac{5}{3}$$
  • $$\dfrac{10}{3}$$
What are the advantages of squaring a difference for calculating variance and standard deviation?
  • Squaring makes each term positive so that values above the mean do not cancel below the mean.
  • Squaring adds more weight to the larger differences, and in many cases this extra weight is appropriate since points further from the mean may be more significant.
  • It complicates the calculations
  • All are incorrect
In how many of the given years was the production of fertilizers more than the average production of the given years?
548316.jpg
  • 1
  • 2
  • 3
  • 4
For how many companies has there been no decrease in production in any year from the previous year?
548659.jpg
  • One
  • Two
  • Three
  • Four
In which pair of years was the number of candidates qualified, the same?

547121.JPG
  • 1995 and 1997
  • 1995 and 2000
  • 1998 and 1999
  • Data inadequate
The difference in the sales of cellular phones for the years $$1997$$ and $$1999$$ is?
548625.jpg
  • $$500$$ units
  • $$1,000$$ units
  • $$5,000$$ units
  • $$18,000$$ units
Suppose a researcher is concerned with a nominal scale that identifies users versus nonusers of bank credit cards. The measure of central tendency appropriate to this scale is the
  • Mean
  • Mode
  • Median
  • Average
The average production for five years was maximum for which company?
548219.jpg
  • X
  • Y
  • Z
  • X and Z both
What was the percentage increase in imports from 1997 to 1998 ?
547024.JPG
  • 72
  • 56
  • 28
  • Data inadequate
The degree to which numerical data tend to spread about value is called
  • mean
  • variation
  • median
  • mode
All the students of a class performed poorly in Mathematics. The teacher decided to give grace marks of $$10$$ to each of the students. Which of the following statistical measures will not change even after the grace marks were given.
  • Median
  • Mode
  • Variance
  • Mean
If $$x $$ is increased by $$k$$ then $$\sigma$$  changes to
  • $$k+\sigma$$
  • $$k\sigma$$
  • $$k\sqrt{\sigma}$$
  • remains unchanged
Variance of the first $$11$$ natural numbers is:
  • $$\sqrt{5}$$
  • $$\sqrt{10}$$
  • $$5\sqrt{2}$$
  • $$10$$
If $$x $$ is multiplied by $$k$$ then $$\sigma$$  changes to
  • $$k^2\sigma$$
  • $$k\sigma$$
  • $$k\sqrt{\sigma}$$
  • $$k(\sigma)^2$$
Standard Deviation of n observations $$a_1, a_2, a_3 .....a_n$$ is $$\sigma$$ Then the standard deviation of the observations $$\lambda a_1, \lambda a_2, ..., \lambda a_n$$ is
  • $$\lambda \sigma$$
  • $$-\lambda \sigma$$
  • $$|\lambda| \sigma$$
  • $${\lambda}^n \sigma$$
The formula to find variance is 
  • $${\dfrac{\sum x^2}{n}-\left(\dfrac{\sum x}{n}\right)}$$
  • $${\dfrac{\sum x^2}{n}-\left(\dfrac{\sum x}{n}\right)^2}$$
  • $${\dfrac{\sum x^2}{n}-(\overline x)^2}$$
  • $${\dfrac{\sum x}{n}-\left(\dfrac{\sum x}{n}\right)^2}$$
The standard deviation of $$a,a+d,a+2d,...,a+{2}{n}d$$ is
  • $$nd$$
  • $${n}^{2}d$$
  • $$\sqrt { \cfrac { n(n+1) }{ 3 } } d\quad $$
  • $$\sqrt { \cfrac { n(n+3) }{ 3 } } d\quad $$
If the variance of a data is $$12.25$$, then the standard deviation is
  • $$3.5$$
  • $$3$$
  • $$2.5$$
  • $$3.25$$
Find the variance of the following distribution.
Class interval
$$20-24$$
$$25-29$$
$$30-34$$
$$35-39$$
$$40-44$$
$$45-49$$
Frequency
$$15$$
$$25$$
$$28$$
$$12$$
$$12$$
$$8$$
  • $$416$$
  • $$46$$
  • $$16$$
  • None of these
The mean and the variance of $$10$$ observations are given to be $$4$$ and $$2$$ respectively. If every observation is multiplied by $$2$$, the mean and the variance of the new series will be respectively.
  • $$8$$ and $$20$$
  • $$8$$ and $$4$$
  • $$8$$ and $$8$$
  • $$80$$ and $$40$$
Calculate the standard deviation of the following data.
x
$$3$$
$$8$$
$$13$$
$$18$$
$$23$$
f
$$7$$
$$10$$
$$15$$
$$10$$
$$8$$
  • $$6.32$$.
  • $$2.32$$.
  • $$3.32$$.
  • None of these
What is the combined standard deviation of all 250 items ?
  • $$7.45$$
  • $$7.35$$
  • $$7.98$$
  • $$7.73$$
Let X denote the number of scores which exceed 4 in 1 toss of a symmetrical die. Consider the following statements :
The arithmetic mean of X is
The standard deviation of X is
Which of the above statements is/are correct ?
  • 1 only
  • 2 only
  • Both 1 and 2
  • Neither 1 nor 2
The variance of numbers $$x_1, x_2, x_3,..... x_n$$ is V. Consider the following statements : 
If every $$x_1$$, is increased by 2, the variance of the new set of numbers is V.
If the numbers $$x_1$$ is squared, the variance of the new set is $$V^2$$.
Which of the following statements is/are correct ?
  • 1 only
  • 2 only
  • Both 1 and 2
  • Neither 1 nor 2
Calculate the standard deviation of the first $$13$$ natural numbers.
  • $$3.74$$.
  • $$2.74$$.
  • $$3.48$$.
  • None of these
The variance of first '$$n$$' natural number is
  • $$\dfrac { { n }^{ 2 }+1 }{ 12 } $$
  • $$\dfrac { { n }^{ 2 }-1 }{ 12 } $$
  • $$\dfrac { \left( n+1 \right) \left( 2n+1 \right) }{ 6 } $$
  • None of these
Calculate the standard deviation of the following data.
$$10, 20, 15, 8, 3, 4$$
  • $$5.97$$
  • $$59.7$$
  • $$4.97$$
  • None of these
What is the ratio of the total sales of branch B2 for both years to the total sales of branch B4 for both years?
672003_466c0b5660064998af4eefd3d8593143.PNG
  • 2:3
  • 3:5
  • 4:5
  • 7:9
If the mean of the numbers $$a,b,8,5,10$$ is $$6$$ and their variance is $$68$$, then $$ab$$ is equal to
  • $$6$$
  • $$7$$
  • $$12$$
  • $$14$$
  • $$25$$
For the data set below, which value is in the 75th percentile?
$$1, 3, 3, 4, 6, 7, 7, 7, 8, 9, 9, 10, 12, 15, 16, 17$$
  • 16
  • 9
  • 12
  • 15
What is the total expenditure (Rs. in lakhs) of the company during the period January to July in the year 2003?
677815_fc50b4f858314305afcae9803818efa6.png
  • $$3,800$$
  • $$3,950$$
  • $$4,600$$
  • $$5,350$$
If the variance of $$1, 2, 3, 4, 5, ..., x$$ is $$10$$, then the value of $$x$$ is
  • $$9$$
  • $$13$$
  • $$12$$
  • $$10$$
  • $$11$$
For the information given below,Find quartile deviation and coefficient of quartile deviation
Maximum Load
      Number of Cables
9.3-9.722
9.8-10.255
10.3-10.712
10.8-11.217
11.3-11.714
11.8-12.266
12.3-12.733
12.8-13.211
  • $$0.275,0.065$$
  • $$0.495,0.045$$
  • $$0.415,0.055$$
  • $$0.225,0.012$$
The arithmetic mean of the observations 10,8,5,a,b is 6 and their variance 6.Then ab=
  • 6
  • 4
  • 3
  • 12
Mean of $$10$$ observations is $$50$$ and their standard deviation is $$10$$. If each observation is subtracted by $$5$$ and then divided by $$4$$, then the new mean and standard deviation are
  • $$22.45, 2.5$$
  • $$11.25, 2.5$$
  • $$11.5, 2.5$$
  • $$11, 2.5$$
  • $$11.75, 2.5$$
What is the average monthly expenditure (Rs. in lakhs) for January to July during the year 2005?
677817_a79032d81c414754bec1044973bc3336.png
  • $$658.3$$
  • $$766.7$$
  • $$764.2$$
  • $$657.1$$
The line graph show the number of cars Jatin sold over the past $$5$$ weeks.
If he was paid $$Rs \ 20000$$ for every car sold, how much was he paid over the past $$5$$ weeks?

722968_718f381f289144e4b7934b6c646e8bf2.png
  • $$Rs \ 280000$$
  • $$Rs \ 240000$$
  • $$Rs \ 480000$$
  • $$Rs \ 500000$$
The given pictograph shows the number of wall clocks sold by a company during a week. Each clock in the pictograph represents $$5$$ wall clocks. How many wall clocks were sold during the week?

722975_2da5fcd7ac8e43d0b23b4d07bc3d9c4d.png
  • $$101$$
  • $$110$$
  • $$120$$
  • $$115$$
Which of the above states is the largest producer of wheat?
724141_ea843bd0314e49589b5ad210c1ce7873.png
  • M.P.
  • Haryana
  • Maharashtra
  • U.P.
If the sum and sum of squares of $$10$$ observations are $$12$$ and $$18$$ resp., then, The $$S.D$$ of observations is :-
  • $$\dfrac{1}{5}$$
  • $$\dfrac{2}{5}$$
  • $$\dfrac{3}{5}$$
  • $$\dfrac{4}{5}$$
An Um contains $$4$$ white and $$3$$ red balls. $$X$$ is the no. of red balls. Find the Mean and Variance of $$X$$.
  • $$\dfrac {9}{7}, \dfrac {24}{49}$$
  • $$\dfrac {9}{7}, \dfrac {25}{48}$$
  • $$\dfrac {9}{8}, \dfrac {24}{49}$$
  • $$\dfrac {9}{8}, \dfrac {24}{48}$$
Find the Quartile Deviation for the following set of data:
$$490, 540, 590, 600, 620, 650, 680, 770, 830, 840, 890, 900$$
  • $$12$$
  • $$122.5$$
  • $$13$$
  • $$12.6$$
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