Answer:
(53.3; 56.1)
Step-by-step explanation:
Given that:
Sample size, n = 41
Mean, xbar = 54.7
Standard deviation, s = 5.3
Confidence level, Zcritical at 90% = 1.645
Confidence interval :
Xbar ± Margin of error
Margin of Error = Zcritical * s/sqrt(n)
Margin of Error = 1.645 * 5.3/sqrt(41)
Margin of Error = 1.362
Lower boundary = 54.7 - 1.362 = 53.338
Upper boundary = 54.7 + 1.362 = 56.062
(53.3 ; 56.1)
Answer:
x = -2
y = -5
Step-by-step explanation:
We can solve this algebraically (substitution or elimination) or graphically. I will be using elimination:
Step 1: Add the 2 equations together
-8y = 40
y = -5
Step 2: Plug <em>y </em>into an original equation to find <em>x</em>
-3(-5) + 10x = -5
15 + 10x = -5
10x = -20
x = -2
And we have our final answers!
Answer:
product of prime factors: 2*5
11 is the coefficient of r and 7 is the coefficient of s
Answer:
C
Step-by-step explanation:
To factorise the quadratic
Consider the factors of the constant term (- 39) which sum to give the coefficient of the x- term (- 10)
The factors are - 13 and + 3, since
- 13 × 3 = - 39 and - 13 + 3 = - 10, hence
x² - 10x - 39 = (x - 13)(x + 3) ← in factored form
x - 13 is a factor → C
