S+d=209
d=209-s
6.5s+2d=836.5
6.5s+2(209-s)=836.5
6.5s+418-2s=836.5
4.5s+418=836.5
4.5s=418.5
s=93
There were 93 salads sold that day.
Answer:
The general rule is ![a_n = -2 - 5(n-1)](https://tex.z-dn.net/?f=a_n%20%3D%20-2%20-%205%28n-1%29)
Step-by-step explanation:
Arithmetic sequence:
In an arithmetic sequence, the difference between consecutive terms is always the same, and this difference is called common difference.
The general rule of an arithmetic sequence is given by:
![a_{n} = a_1 + (n-1)d](https://tex.z-dn.net/?f=a_%7Bn%7D%20%3D%20a_1%20%2B%20%28n-1%29d)
In which
is the first term and d is the common difference.
We can also find the nth term as a function of a term m, using:
![a_n = a_m + (n-m)d](https://tex.z-dn.net/?f=a_n%20%3D%20a_m%20%2B%20%28n-m%29d)
a3 = -12 and a8 = -37
First we find the common difference. So
![a_n = a_m + (n-m)d](https://tex.z-dn.net/?f=a_n%20%3D%20a_m%20%2B%20%28n-m%29d)
![a_8 = a_3 + (8-3)d](https://tex.z-dn.net/?f=a_8%20%3D%20a_3%20%2B%20%288-3%29d)
![-37 = -12 + 5d](https://tex.z-dn.net/?f=-37%20%3D%20-12%20%2B%205d)
![5d = -25](https://tex.z-dn.net/?f=5d%20%3D%20-25)
![d = -\frac{25}{5}](https://tex.z-dn.net/?f=d%20%3D%20-%5Cfrac%7B25%7D%7B5%7D)
![d = -5](https://tex.z-dn.net/?f=d%20%3D%20-5)
So
![a_n = a_1 - 5(n-1)](https://tex.z-dn.net/?f=a_n%20%3D%20a_1%20-%205%28n-1%29)
Finding the first term:
![a_n = a_1 - 5(n-1)](https://tex.z-dn.net/?f=a_n%20%3D%20a_1%20-%205%28n-1%29)
Since ![a_3 = -12](https://tex.z-dn.net/?f=a_3%20%3D%20-12)
![a_n = a_1 - 5(n-1)](https://tex.z-dn.net/?f=a_n%20%3D%20a_1%20-%205%28n-1%29)
![a_3 = a_1 - 5(3-1)](https://tex.z-dn.net/?f=a_3%20%3D%20a_1%20-%205%283-1%29)
![a_1 = a_3 + 10 = -12 + 10 = -2](https://tex.z-dn.net/?f=a_1%20%3D%20a_3%20%2B%2010%20%3D%20-12%20%2B%2010%20%3D%20-2)
So the general rule is:
![a_n = a_1 - 5(n-1)](https://tex.z-dn.net/?f=a_n%20%3D%20a_1%20-%205%28n-1%29)
![a_n = -2 - 5(n-1)](https://tex.z-dn.net/?f=a_n%20%3D%20-2%20-%205%28n-1%29)
Answer: see below
Step-by-step explanation:
(i)
200/2 = 100
Find 100 on cumulative frequency and the correspinding time: 14 minutes. So the answer is 14 minutes.
(ii)
First, find the lower quartile —> 200/4 = 50
Upper quartile —> 200/(3/4) = 150
Find the difference: 150 - 50 = 100
So the interquartile range is 100
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Answer:
Step-by-step explanation:
From the information given,
Mark: 6,7,8,9,10
frequency:5,4,7,10,4
a) Range = highest mark - lowest mark
Range = 10 - 6 = 4
b) The number of students in the group is the sum of the frequency. Therefore,
Number of students = 5 + 4 + 7 + 10 + 4 = 30 students
c) Mean mark = (mark × frequency)/total frequency
[(6 × 5) + (7 × 4) + (8 × 7) + (9 × 10) + 10 × 4)]/ 30
Mean mark = (30 + 28 + 56 + 90 + 40)/30 = 244/30
Mean mark = 8.1
Answer:
2.25 it is the answer
Step-by-step explanation: