Consider the formula for surface area, SA = (p • h) + 2B. The perimeter is
2 answers:
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Answer:
The mean of 25 students is 17.6
Step-by-step explanation:
The formula of the mean (average) is mean (average) = , where S is the sum of the data, and N is the number of the data
∵ The average marks of the first 10 students are 17
- That means the mean is 17 and the number of students is 10
∴ Average = 17
∴ N = 10
∵ Average =
- Substitute average by 17 and N by 10
∴ 17 =
- Multiply both sides by 10
∴ 170 = S
∴ The sum of the marks of the first 10 students is 170
∵ The average of the next 15 students is 18
∴ Average = 18
∴ N = 15
- Substitute average by 18 and N by 15
∴ 18 =
- Multiply both sides by 15
∴ 270 = S
∴ The sum of the marks of the next 15 students is 270
Now to find the mean of 25 students and the two sums and divide the answer by 25
∵ S = 170 + 270
∴ S = 440
∵ N = 25
∴ Mean =
∴ Mean = 17.6
The mean of 25 students is 17.6
Answer: POQ = 125
Step-by-step explanation: If you don’t want to read my long explanation, I drew a diagram of my work. :>
First we need to establish that POQ is a vertical angle to SOT, this makes the angles equal. We also need to establish that because the definition of an altitude, that T And S both form right angles. (An altitude is a perpendicular segment from a vertex of a triangle to the opposite side.) Now let’s take a look at the quadrilateral that is formed inside the triangle, the quadrilateral being RSOT. Luckily we know the measure of three of the angles, R=55, T=90, and S=90. If you didn’t know beforehand all angles of a quadrilateral add up to 360, so we can add up the angles we’ve already found to find the missing angle O/ SOT. When we add the angles, and then subtract that from 360 we get 125, so SOT=125. Remember that we established that SOT and POQ are vertical angles, so if SOT=125 then POQ=125.
I really hoped my explanation was good, this was my first time giving an answer. Also I’m sorry if my method of finding the answer wasn’t helpful, but this was the only way I could think of.
I accidentally gave myself a one star rating, that sucks.
