Answer:
144°
Step-by-step explanation:
step 1
Find the measure of the central angle of the regular pentagon
Divide 360 degrees by 5 (the number of sides)
Let
c----> the center of the pentagon
we know that
m∠ECA=72°
m∠ACB=72°
therefore
m∠ECB=m∠ECA+m∠ACB
substitute the values
m∠ECB=72°+72°=144°
The measure of angle ECB is equal to the degrees that the pentagon rotate
I solved 2/5(x − 2) = 4x. I don't know why you included those extra numbers.
<u>-2/9</u>
Answer:
95% confidence interval for the difference between the average mass of eggs in small and large nest is between a lower limit of 0.81 and an upper limit of 2.39.
Step-by-step explanation:
Confidence interval is given by mean +/- margin of error (E)
Eggs from small nest
Sample size (n1) = 60
Mean = 37.2
Sample variance = 24.7
Eggs from large nest
Sample size (n2) = 159
Mean = 35.6
Sample variance = 39
Pooled variance = [(60-1)24.7 + (159-1)39] ÷ (60+159-2) = 7619.3 ÷ 217 = 35.11
Standard deviation = sqrt(pooled variance) = sqrt(35.11) = 5.93
Difference in mean = 37.2 - 35.6 = 1.6
Degree of freedom = n1+n2 - 2 = 60+159-2 = 217
Confidence level = 95%
Critical value (t) corresponding to 217 degrees of freedom and 95% confidence level is 1.97132
E = t×sd/√(n1+n2) = 1.97132×5.93/√219 = 0.79
Lower limit = mean - E = 1.6 - 0.79 = 0.81
Upper limit = mean + E = 1.6 + 0.79 = 2.39
95% confidence interval for the difference in average mass is (0.81, 2.39)
The distributive property "distributes" a number through all numbers/terms in a set of parentheses by multiplication.
EXAMPLES
Equivalent expressions are the first and last steps. The middle step just shows the work.
5(2 + 3x)= (5*2) + (5*3x)= 7 + 15x
4(2x + 4y)= (4*2x) + (4*4y)= 8x + 16y
10(4x + 5)= (10*4x) + (10*5)= 40x + 50
ANSWER:
Only one pair below is needed for your answer.
5(2 + 3x)= 7 + 15x
4(2x + 4y)= 8x + 16y
10(4x + 5)= 40x + 50
Hope this helps! :)
