### Moving average method - Class IX

Description: moving average method | |

Number of Questions: 37 | |

Created by: Mira Shah | |

Tags: maths time series business maths statistics time series and forecasting linear regression regression analysis analyzing data moving averages |

A train running at $\dfrac{7}{{11}}$ of its own speed reached a place in 22 hours. How much time could be saved if the train would have run at its own speed ?

The total numbers of squares on a chessboard is

The average weight of $A,B,C$ is $45kg$ . If the average weight of $A$ and $B$ be $40kg$ and that of $B$ and $C$ be $43kg$, find the weight of $B$ ?

In a call of 100 students there are 70 boys whose average marks in a subject is 75. If the average marks of the complete class is 72 . then the average marks of the girls is

.Twelve years hence a man will be four times as he was twelve years ago, then his present age is

Moving-averages:

The problem given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statements(s) is / are necessary to answer the question.

How many marks did Tarun secure in English?

(i)The average marks obtained by Tarun in four subjects including English are 60.

(ii) The total marks obtained by him in English and Mathematics together are 170.

(iii)The total marks obtained by him in Mathematics and science together are 180.

Choose the correct answer from the alternatives given.

A man covers a distance of $160$ km at $64 km/hr$ and next $160$ km at $80 km/hr$. What is his average speed for his whole journey of $320$ km?

Bira and his wife Sheena have two daughters aged $12$ and $16$. Sheena's mother and father, aged $65$ and $72$, also live with them. Bira is currently looking for work, but can't find any. His elder daughter completed class $10$ and prefers to look for work. Sheena prefers to stay at home to look after house works. How many unemployed members does Bira's family have?

A qualitative forecast

Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?

The first step in time-series analysis is to

In moving average method, we cannot find the trend values of some:

The method of least squares dictates that we choose a regression line where the sum of the square of deviations of the points from the line is:

In simple linear regression, the numbers of unknown constants are:

If one regression coefficient is greater than one, then other will be:

The purpose of simple linear regression analysis is to:

Ayushi used the data from a scatterplot to determine a regression model showing the relationship between the population in the area where she lived and the number of years, $x$, after she was born. The result was an exponential growth equation of the form $y={x} _{0}{\left(1+r\right)}^{x}$. Then ${x} _{0}$ most likely represents

The independent variable in a regression line is:

In regression analysis, if observed cost value is $50$ and predicted cost value is $7$ then disturbance term is

State true or false: The coefficient of correlation between two variables $x$ and $y$ is:

$r=\cfrac { { \sigma }^{ 2 }x+{ \sigma }^{ 2 }y-y }{ 2{ \sigma }_{ x }{ \sigma } _{ y } } $

The sum of the difference between the actual values of $Y$ and its values obtained from the fitted regression line is always:

If all the actual and estimated values of $Y$ are same on the regression line, the sum of squares of error will be:

The regression lines will be perpendicular to each other if the coefficient of correlation r is equal to.

Find the equation of $y$ on $x$ on the basis of the following data:

$x$ | $5$ | $2$ | $1$ | $4$ | $3$ |
---|---|---|---|---|---|

$y$ | $5$ | $8$ | $4$ | $2$ | $10$ |

Which of the following statements is/are correct in respect of regression coefficients?

$1.$ It measures the degree of linear relationship between two variables.

$2.$ It gives the value by which one variable changes for a unit change in the other variable.

Select the correct answer using the code given below.

For 10 observations on price (x) and supply (y), the following data was obtained: $\sum x = 130, \sum y = 220, \sum x^2 = 2288, \sum y^2 = 5506$ and $\sum xy = 3467$.

What is the line of regression of y on x?

For two variables $x$ and $y$ ,the following data are given as

$\Sigma x=125,\Sigma y=100, \Sigma x^2=1650,\Sigma y^2=1500,\Sigma xy=50,n=25$.Find the value of $x$ when $y=5$

Consider the following statements: (1) If the correlation coefficient ${ r } _{ xy }=0$, then the two lines of regression are parallel to each other (2) If the correlation coefficient ${ r } _{ xy }=+1$, then the two lines of regression are perpendicular to each other? Which of the above statements is/are correct?

Find the Value of $y$ from the following data when $x=70$ and coefficient of correlation $0.8$.

Series | $x$ | $y$ |
---|---|---|

A.M | $18$ | $100$ |

Standard Deviation | $14$ | $20$ |

Find the equation of $x$ on $y$ on the basis of the following data:

$x$ | $2$ | $4$ | $6$ | $8$ | $10$ |
---|---|---|---|---|---|

$y$ | $6$ | $5$ | $4$ | $3$ | $2$ |

If $4\bar {x}-5\bar y+33=0$ and $20\bar x-9\bar y=107$ are two lines of regression, then what are the values of $\bar { x } $ and $\bar { y } $ respectively.

For the variables $x$ and $y$, the regression equations are given as $7x-3y-18=0$ and $4x-y-11=0$. Identify the regression equation of $y$ on $x$.

What would be the estimated sale on the advertisement expenditure of Rs $15$ lakhs,on the basis of following data obtained from the company?.The coefficient of correlation is $0.8$.

Advertising expenditure(in Rs.lakhs) $x$ | Sale (in Rs lakhs) $y$ | |
---|---|---|

Mean | $20$ | $90$ |

standard Deviation | $5$ | $12$ |

Find the equation of $y$ on $x$ for the following data

$x$ | $8$ | $6$ | $4$ | $7$ | $5$ |
---|---|---|---|---|---|

$y$ | $9$ | $8$ | $5$ | $6$ | $2$ |

For the variables $x$ and $y$, the regression equations are given as $7x-3y-18=0$ and $4x-y-11=0$. Find the arithmetic means of $x$ and $y$ respectively.

The two lines of regression are $x+2y-5=0$ and $x+3y-8=0$. The coefficient of correlation between $x$ and $y$ is