The prices and the quantities of three commodities are given are :

Commodity	Price (₹) in Year 2006	Price (₹) in Year 2009	Quantities in Year 2006	Quantities in Year 2009
P	100	90	12	10
Q	80	$x$	8	7
R	60	50	4	6

The Laspeyre's price index number for year 2009 with year 2006 as base is 200. The value of $x$ is :

Irregular variations in a time series are caused by:

A. Floods

B. Natural calamities

C. Labour strike

D. Climate changes

Choose the correct answer from the options given below:

From the data given below the Laspeyre's price index for the year 2016 with year 2010 as base year is

The price relatives and weights of a set of commodities are given as:

If the sum of weights is 30 and the index for the set is 144, then the values of $x$ and $y$ are:

Consider the following data :

The equation of the straight line trend by the method of least squares is :

Using simple average of relatives method, the price index for 2011, taking 2001 as base year, was found to be 127. If $\Sigma p_0 = 263$, then x and y from the following data are :

For the given five values, 17, 25, 21, 35, 43, the three-year moving averages are: