Question

what is the mean? 7 4 4 5 1 9

Explanation:

Step1: Sum the numbers

To find the mean, first we sum all the given numbers. The numbers are 7, 4, 4, 5, 1, 9. So the sum is \(7 + 4 + 4 + 5 + 1 + 9\). Let's calculate that: \(7+4 = 11\), \(11 + 4 = 15\), \(15 + 5 = 20\), \(20 + 1 = 21\), \(21 + 9 = 30\). So the sum is 30.

Step2: Count the numbers

Next, we count how many numbers there are. The numbers are 7, 4, 4, 5, 1, 9. Let's count them: 1 (7), 2 (4), 3 (4), 4 (5), 5 (1), 6 (9). So there are 6 numbers.

Step3: Calculate the mean

The mean is the sum of the numbers divided by the count of the numbers. So we divide the sum (30) by the count (6). The formula for the mean \(\bar{x}\) of a set of numbers \(x_1, x_2, \dots, x_n\) is \(\bar{x}=\frac{\sum_{i = 1}^{n}x_i}{n}\). Here, \(\sum_{i = 1}^{n}x_i = 30\) and \(n = 6\), so \(\bar{x}=\frac{30}{6}=5\).

Answer:

5