A study of the effect of television commercials on 12-year-old children measured their attention span, in seconds. The commercials were for clothes, food, and toys. Clothes Food Toys
43 30 52
24 38 58
42 46 43
35 54 49
28 47 63
31 42 53
17 34 48
31 43 58

Required:
a. Find the values of mean and standard deviation.
b. Is there a difference in the mean attention span Of the children for the various commercials?

(a)

Mean

Standard deviation

(b) Yes, there is a difference in the mean

Step-by-step explanation:

Solving (a): The mean and standard deviation of each commercial

This is calculated as:

For clothes:

For food:

For toys:

The sample standard deviation is:

For clothes:

For food:

For toys:

Solving (b): Difference in mean in the commercials;

In (a), we have:

Hence, there is a difference in their means

answer: i think it's a

step-by-step explanation:

17   x 256=4352

sorry if this is wrong, i'm new.

step-by-step explanation: