Question

27 131 Marks

Answer 1

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

$42 = \frac{367 + y}{10}$

Multiply both sides by 10

$42 * 10 = \frac{367 + y}{10} * 10$

$420 = 367 + y$

Subtract 367 from both sides

$420 - 367= 367 -367 + y$

$53 = y$

$y = 53$

Hence, the number of sweets in the 10th bag is 53