Recent content by finalight

so that means 120 +- A/sqrt(30) = 117,123 ----------------------------------- Equation 1: 120 - A/sqrt(30) = 117 Equation 2: 120 + A/sqrt(30) = 123 are you referring to something like that?

the general formula would be mean +- confidence level * standard deviation/sqrt(sample size) 120 +- x * s/sqrt(40) = 117,123 120 +- x * s/sqrt(30) = ?,? that's what i got, still can't see the similarity, except for the two unknowns there unless you want me to use simultaneous equation...

yes, i also assume that the standard deviation and the confidence level remain the same however, even with the given formula, i still do not know how to calculate the result, because there are two unknowns; the confidence level and the standard deviation itself

Homework Statement In a primary school, the mean height of the students of primary 1 students is 120cm. Given a sample size of 40, the confidence interval is 117 and 123. Find the confidence interval if the sample size is 30 instead. Homework Equations Standard deviation and confidence level...

sory, just reaize the ± don't belong there so it's a = 2/3b? is tat correct?

i probably need hints on how to describe it without using the form a/b

(x1, y1)Υ(x2, y2) x1, x2 ∈ Z and y1, y2 ∈ Z+ so y1 ∈ Z+ as stated in the question

I don't think (0,0) is a valid ordered pair, since b must be positive integer

the ordered pair i found so far is like this {(3,2), (6,4), (9,6), (12,8)} so the answer would be {(a, b)∈ Z x Z+: b/a = ±2/3} haha, i think i got it correct i'm not sure whether to include the '±', but since y1, y2 could be any ±Z, i have to take precaution

so is the answer like [(3,2)]?

(x1, y1)Υ(x2, y2) ⇔ x1 × y2 = x2 × y1 for all x1, x2 ∈ Z and y1, y2 ∈ Z+ have been shown to be an equivalence relation in tutorial. Specify the equivalence class [(2; 3)] as induced by Υ. i don't understand what it means by 'Specify the equivalence class [(2; 3)] as induced by Υ.'...