The overall mean for all the treatments is:.a. 7.00b. 6.67c. 7.25d. 4.89

The question is not complete, below is the completed question:

in a completely randomized design involving three treatments, the following information is provided.

                              Treatment 1         Treatment 2       Treatment 3

Sample size                   5                            10                       5

Sample mean                4                             8                        9

The overall mean for all the treatments is:.a. 7.00b. 6.67c. 7.25d. 4.89

The correct answer is:

7.25 (c)

Explanation:

To find the overall mean of the treatment, we will use the weighted mean formula.

1) first find the weight of the means by multiplying the means of each treatment by their sample sizes:

Treatment 1: 5 × 4 = 20

Treatment 2 = 10 × 8 = 80

Treatment 3 = 5 × 9 = 45

Grand mean Total weighted means ÷ total sample size = (20 + 80 + 45) ÷ (5 + 10 + 5)

= 145 ÷ 20 = 7.25

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explanation:

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