Answer:
2.54. Calculate the approximate value:2.6 *
Step-by-step explanation:
Answer:
4 cm
Step-by-step explanation:
Perimeter = 18cm
θ = 2.5 radian
s = rθ, s = Arc length
Perimeter of Sector, P = arc length, s + 2r
Perimeter = rθ + 2r
r = Radius
18cm = r(2.5) + 2r
18cm = 2.5r + 2r
18cm = 4.5r
r = 18 /4.5
r = 4
(a) Average time to get to school
Average time (minutes) = Summation of the two means = mean time to walk to bus stop + mean time for the bust to get to school = 8+20 = 28 minutes
(b) Standard deviation of the whole trip to school
Standard deviation for the whole trip = Sqrt (Summation of variances)
Variance = Standard deviation ^2
Therefore,
Standard deviation for the whole trip = Sqrt (2^2+4^2) = Sqrt (20) = 4.47 minutes
(c) Probability that it will take more than 30 minutes to get to school
P(x>30) = 1-P(x=30)
Z(x=30) = (mean-30)/SD = (28-30)/4.47 ≈ -0.45
Now, P(x=30) = P(Z=-0.45) = 0.3264
Therefore,
P(X>30) = 1-P(X=30) = 1-0.3264 = 0.6736 = 67.36%
With actual average time to walk to the bus stop being 10 minutes;
(d) Average time to get to school
Actual average time to get to school = 10+20 = 30 minutes
(e) Standard deviation to get to school
Actual standard deviation = Previous standard deviation = 4.47 minutes. This is due to the fact that there are no changes with individual standard deviations.
(f) Probability that it will take more than 30 minutes to get to school
Z(x=30) = (mean - 30)/Sd = (30-30)/4.47 = 0/4.47 = 0
From Z table, P(x=30) = 0.5
And therefore, P(x>30) = 1- P(X=30) = 1- P(Z=0.0) = 1-0.5 = 0.5 = 50%
Answer:
Step-by-step explanation:
they are opposite angles, so we put them equal to each other.
25.
6a+10= 130
6a=120 a=20 so now we plug it in 6(20) +10= 130
26. 4a-4=2a+30
2a=34 a=17 sso now we plug in 4(17)-4= 64 2(17)+30= 64
27. 6y+1=4y+9 2x-5=x+7
2y=8 x=2
y=4
now plug in 6(4)+1=25 4(4)+9=25 2(2)-5= -1 (2)+7=9
