The first step would be to isolate a variable (solve for a variable)....so u will have something to sub into the other equation
Answer:
r = 49
Step-by-step explanation:
686 = 14r
686/14= 49
r = 49
X = tuna, y = BLT
x + y = 30
6x + 9y = 240
3y = 60
y = 20
x = 10
20 BLTs for $2.50, 10 tuna for $1.50
Answer: = ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b)= ( 63.9, 66.7)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 65.3
Standard deviation r = 5.2
Number of samples n = 36
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
65.3 +/-1.645(5.2/√36)
65.3 +/-1.645(0.86667)
65.3+/- 1.4257
65.3+/- 1.4
= ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b)= ( 63.9, 66.7)
3x+4x+5x=90
combine like terms
12x = 90
divide by 12
x = 7.5
sides: 3(7.5) ,4(7.5) ,5(7.5)
22.5, 30, 37.5
