Answer:
The standard error of the mean = 5.14 mins
Step-by-step explanation:
Number of random sample (n) = 20
Mean(X) = 31.25 mins
Standard deviation (α) = 23.7 mins
Standard error of mean =
standard deviation / √sample size
= 23.7/√20
= 23.7/4.4721
= 5.14 mins
Answer:
45
Step-by-step explanation:
1/6 of 54= 9
9*5=45
Easy, find the equation of the line,
Using y=mx+b form:
(-1,3) m=2
3= 2(-1)+b
3= -2+b
+2 +2
5=b
y=2x+5. This is your equation.
Now, plug in the coordinates:
(-3,2)
2= 2(-3)+5
2= -6+5
2= -1
NO
(0,5)
5= 2(0)+5
5=5
YES
(1,5)
5= 2(1)+5
5= 2+5
5=7
NO
(1,4)
4= 2(1)+5
4= 2+5
4=7
NO.
Thus, B, is your answer.
You know the adjacent and you need to find the opposite, so you would use tangent. Your equation would look like this; tan 26°= x/28. You would need to multiply both sides by 28 to simplify it to this; 28*tan 26°= x
Solving this, you would get an answer of 13.7
Answer:
12 boys
Step-by-step explanation:
From the above question:
Number of boys = 3
Number of girls = 2
Boys: Girls
3:2
Let :
a = boys
b = girls
Hence, a : b = 3 : 2
a/b = 3/2
Cross Multiply
2a = 3b .......... Equation 1
a = 3b/2
If four more girls join the class, there will be the same number of boys and girls
Hence,
a: b + 4 = 3 : 3
a/b + 4 = 3/3
Cross Multiply
3a = 3(b + 4)
3a = 3b + 12 ........ Equation (2)
From Equation 1: a = 3b/2
Substitute 3b/2 for a in Equation 2 we have:
3a = 3b + 12 .........Equation 2
3(3b/2) = 3b + 12
9b/2 = 3b + 12
Cross Multiply
9b = 2(3b + 12)
9b= 6b + 24
9b - 6b = 24
3b = 24
b = 8
Substitute 8 for b in Equation 1
a = 3b/2
a = 3 × 8/2
a = 24/2
a = 12
Therefore, the number of boys in the class is 12
