The expression (2x+1)^2 -2(2x^2-1) is equivalent to:
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Answer:
The number of sweets in the 10th bag is 53
Step-by-step explanation:
Given
Let the Number of sweets in a bag be represented by x and frequency be represented by f
The table is as follows
x F
39 1
40 2
41 5
42 0
43 1
Mean = 42
Required
How many sweets are in the 10th bag?
Represent the number of sweets in the 10th bag by y;
The table becomes
x F
39 1
40 2
41 5
42 0
43 1
y 1
The mean of observation is calculated using the following formula;
Mean = ∑fx/∑f
Where ∑ means summation
fx means f * x; i.e. product of frequency and number of sweets
f represents frequency;
Calculating ∑fx
∑fx = 39 * 1 + 40 * 2 + 41 * 5 + 42 * 0 + 43 * 1 + y * 1
∑fx = 39 + 80+ 205 + 0 + 43 + y
∑fx = 367 + y
Calcuating ∑f
∑f = 1 + 2 + 5 + 0 + 1 + 1
∑f = 10
Recall that
Mean = ∑fx/∑f and Mean = 42;
So, Mean = ∑fx/∑f becomes
Multiply both sides by 10
Subtract 367 from both sides
Hence, the number of sweets in the 10th bag is 53