The mean is 10 because you will add all the numbers and then divide the answer by 4
To answer the question, let x be the cost of a bedsheet and y that of a towel. The first purchase can be expressed as,
38x + 61y = $791.50
and the second as,
54x + 50y = $923
Solving for x and y simultaneously will give, x = $12 and y = $5.5. Thus, each bedsheet costs $12 and each towel cost $5.5.
Answer: 4) 157
Step-by-step explanation:
We know that there is no association between the grade level and the andedness, then we should find that the ratio between left handeds and right handed is the same for both grades.
In 7-th grade we have:
Left handed : 11
Right handed: 72
The ratio is 11/72 = 0.14
Then, the ratio for the 8-th graders must be about the same:
Left handed: 24
Right handed: X
Ratio: 24/X
Let's start with the bigger option, X = 157.
24/157 = 0.15
Ok, we now see that with the bigger option we obtained almost the same ratio (if we use the smaller values for X, we will get a ratio bigger than 0.15, so 0.15 is the better aproximation that we can find to the 0.14 of the 7-th graders)
Then the correct option is 4) 157
