Answer:
130 times .32
Step-by-step explanation:
Answer:
Step-by-step explanation:
step 1
Find the circumference of the circle
The circumference is equal to
we have
substitute
step 2
we know that
The circumference of a circle subtends a central angle of 360 degrees
so
using proportion
Find out the arc length by a central angle of 168 degrees
We first calculate the z-score corresponding to x = 1075 kWh. Given the mean of 1050 kWh, SD of 218 kWh, and sample size of n = 50, the formula for z is:
z = (x - mean) / (SD/sqrt(n)) = (1075 - 1050) / (218/sqrt(50)) = 0.81
From a z-table, the probability that z > 0.81 is 0.2090. Therefore, the probability that the mean of the 50 households is > 1075 kWh is 0.2090.
Answer:
(0.869, 12.33104)
Step-by-step explanation:
N1 = 110
N2 = 225
S1 = 24.8
S2 = 25.8
Bar x1 = 169.9
Bar x2 = 163.3
Difference in mean = 169.9 - 163.3 = 6.6
We use the z score
Alpha = 0.05
Z critical value at this alpha level = 1.96
We find standard error
√s1²/n1+s2²/n2
= √(24.8²/110 + 25.8²/225)
= 2.9239
Confidence interval
6.6 +-1.96(2.924)
(6.6-5.73104, 6.6+5.73104)
= (0.869, 12.331)
