Given series is 2.4,-4.8,9.6,-19.2
To find whether it has common difference or common ratio let us find few differences and few ratios of consecutive terms.
Common difference of first 2 terms = 2nd term - first term = -4.8-2.4 = -7.2
Common difference of 2nd and 3rd terms = 3rd term - 2nd term = 9.6-(-4.8) = 14.4
Since those common differences are not equal the given series does not have common difference at all.
To check if it has common ratio or not let us find few ratios of consecutive terms.
Common ratio of first 2 terms =
= 
Common ratio of 2nd and 3rd terms = 
So, the given series has common ratio as -2.0
The present age of Jane is 45 years old and present age of her sister is 9 years old
<em><u>Solution:</u></em>
Let the present age of Jane be "x"
Let the present age of her sister be "y"
<em><u>Jane is 5 times older than her sister</u></em>
present age of Jane = 5(present age of her sister)
x = 5y ---------- eqn 1
<em><u>In 3 years, Jane’s sister will be 1/4 her age</u></em>
Age of sister after 3 years = 3 + y
Age of jane after 3 years = 3 + x
Age of sister after 3 years = 1/4(age of jane after 3 years)

Substitute eqn 1 in above equation

Substitute y = 9 in eqn 1
x = 5(9)
x = 45
Thus present age of Jane is 45 years old and present age of her sister is 9 years old
A 95% confidence interval for the proportion of non-fatal accidents involving a distracted driver using some kind of electronic device is 62.5%<x<71.61%
The 95% confidence interval for the proportion is expressed according to the formula;

p is the proportion = 268/400 = 0.67
z is the 95% z-score = 1.96
n is the sample space = 400
Substitute the given parameters into the formula to have:

Hence a 95% confidence interval for the proportion of non-fatal accidents involving a distracted driver using some kind of electronic device is 62.5%<x<71.61%
Learn more on confidence interval here: brainly.com/question/17212516
Ask if you don't understand or whatever
hi!
so you're trying to find the value of <em>n</em>, I assume.
(n +2) / 5 = -3
n + 2 = -3 * 5
n + 2 = -15
n = -17
hope this helped!