Answer:
d. There is a 98% chance that the true proportion of customers who click on ads on their smartphones is between 0.56 and 0.62.
Step-by-step explanation:
Confidence interval:
x% confidence
Of a sample
Between a and b.
Interpretation: We are x% sure(or there is a x% probability/chance) that the population mean is between a and b.
In this question:
I suppose(due to the options) there was a small typing mistake, and we have a 98% confidence interval between 0.56 and 0.62.
Interpreation: We are 98% sure, or there is a 98% chance, that the true population proportion of customers who click on ads on their smartphones is between 0.56 and 0.62. Option d.
Answer:
Arts=295, Commerce=177
Step-by-step explanation:
That the three subjects have a common ratio implies that there is some common factor between them that relates to the actual number of students in each area, so 5:4:3 means 5x:4x:3x for some value of x
We know that there are 236 science students, so 4x = 236 or x = 59
so the number of arts students is 5(59) and the number of commerce students is 3(59)
Arts = 5*59 = 295
Commerce = 3*59=177
(I'm going to use brackets as my absolute value bars lol)
[5 x -3]
[-15]
=15
Let r = usual driving rate
let t = usual driving time
We need to figure out t
The distance she covers in her usual time at her usual rate is r*t
The distance she covers in her new time at her new rate is:
(1+t)*((2/3)r)
Set this equal to each other and solve for t.
rt = (2/3)r + (2/3)rt
(1/3)rt = (2/3)r
(1/3)t = (2/3)
t = 2
So her usual time is 2 hours. (There's probably a faster way to do this)