Calculate the mean given the frequency table Class
Frequency
0-9
24
10-19
20
20-29
32

~15.55 is the mean.

Step-by-step explanation:

The class of frequency is given as 0-9, 10-19 and 20-29.

First of all, let us taken middle value of class:

Formula for mean:

where f is the frequency

and m is the mean value calculated in above step (4.5, 14.5 and 24.5)

The frequencies are given as:

4.5 -  24

14.5 - 20

24.5 - 32

Putting the values in above formula:

Please refer to the attached image that contains the table for calculation of mean.

So, mean = ~15.55

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.

phosphate, calcium ion, chloride ion, neon atom

step-by-step explanation: