So, since P are the total number of elements and P_k is the P_kth student. This is saying if we sum over each student's score and divide it by the number of students, we should get P, which is true.

So, using that logic, the other class can be represented as:

$\frac{\sum_{k=1}^{N} N_k}{N}=70$

We can take both of these equations and multiply them by N:

$\sum_{k=1}^{P} P_k=70P$

$\sum_{k=1}^N N_k=92N$

So, if we want to find the average of this we should add both our equations then divide by P+N, which is the number of all the students.

$\frac{\sum_{k=1}^{P} P_k+\sum_{k=1}^{N}N_k}{N+P}=\frac{70P+92N}{N+P}$

To make this simpler we can replace our LHS with 86, since that's the average of both classes combined.

$86=\frac{92N+70P}{N+P} \implies\\ 86N+86P=92N+70P \implies \\ 16P=6N \implies \\ \frac{16P}{N}=6 \implies \\ \frac{P}{N}=\frac{6}{16}$

Simplified we would have P/N=3/8.

7 0

3 years ago

There are 48 calories of energy in 40g of rice. How many calories are in 160 g of rice?

Rashid [163]

160 grams of rice is four times larger than the given 40 g.
<span>So the number of Calories must be 4 times larger too. </span>

<span>48 x 4 = 192 Calories in 160 g of rice</span>

5 0

3 years ago

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Sam had four tests last month. His scores were 81, 94, 83, and 91. What is the median of his scores?

Novay_Z [31]

Answer:

To find the median, the data should be arranged in order from least to greatest. If there is an even number of items in the data set, then the median is found by taking the mean (average) of the two middlemost numbers.

81,83,91,94

since its an even number add up the two middle numbers 83 and 91 to equal 174 then divide by two to have the median of 87

Step-by-step explanation:

3 0

3 years ago

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