Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present
Answer:
314 cm²
Step-by-step explanation:
To find the area of a circle, use the formula A = πr² by substituting r = 10.
A = πr² = π10² = 314 cm²
Answer:
The answer is false
Step-by-step explanation:
In a sample above 30 obs like this the confidence interval is defined as
X+- t* (s/sqrt(n)) where X is the mean t the tvalue for a given confidence level, n the size of sample and s standar deviation.
To find de appropiate value of t we must see the T table where rows are degrees of freedom and columns significance level
The significance is obtained:
significance = 1 - confidence level = 1 - 0.9 = 0.10
Degrees of freedom (df) for the inteval are
df = n - 1 = 18 - 1 = 17
So we must look for the value of a t with 17 values and significance of 0.10 which in t table is 1.740 not 1.746 ( thats the t for 16 df)
Answer:
3x+2Y=10
6×-5-1×=0
Step-by-step explanation:
6-5-1=0
Answer:
44,000
Step-by-step explanation:
The number 3 is in the thousands place. Round that to 4.
Your answer is 44000.
