For large sample confidence intervals about the mean you have:
xBar ± z * sx / sqrt(n)
where xBar is the sample mean z is the zscore for having α% of the data in the tails, i.e., P( |Z| > z) = α sx is the sample standard deviation n is the sample size
We need only to concern ourselves with the error term of the CI, In order to find the sample size needed for a confidence interval of a given size.
z * sx / sqrt(n) = width.
so the z-score for the confidence interval of .98 is the value of z such that 0.01 is in each tail of the distribution. z = 2.326348
The equation we need to solve is:
z * sx / sqrt(n) = width
n = (z * sx / width) ^ 2.
n = ( 2.326348 * 6 / 3 ) ^ 2
n = 21.64758
Since n must be integer valued we need to take the ceiling of this solution.
n = 22
sara speed is half of Jeanette's so if jeanette ran 7 miles then her walking speed is 3.5MPH and sense she is 7 miles ahed sara is 10.5 miles behind... 3.5MPH which is jeanette speed is double than sara so 3.5/2 is 1.75MPH... Saras walking speed is 1.75MPH
Answer:
$9,000.00 is her original investment worth in 10 yrs.
5000 x 1.08 ^10 = 10794.6249864
Then subtract -500000 = 5794.62498636
Step-by-step explanation:
Why, because the first year is proved 5000 x 0.08 = 400
= 400 year 1 but cna keep only if stays in investment for 10 years
400 x 10 = 4000 interest on investment
5000+ 4000 = $9,000.00 SI
+ 1,794.62 Interest on interest if applies (this is called CI) and makes $10794.62
Tigers:-
f(t) = 7(1 + 0.1)^2 where t = number of years
Eagle
g(t) = 15 + 2t
B after ten year number tigers = f(t) = 7(1 + 0.1)^10 = 18
number of eagles = 15 + 10(2) = 35
C when the number of tigers = number eagles the 2 functions will be equal;-
f(t) = g(t) that is:-
7* 1.1^t = 15 + 2t
solve for t
Answer:
D) 20.
Step-by-step explanation:
First find the value of x using Pythagoras theorem:
10^2 = x^2 + (2x)^2
5x^2 = 100
x^2 = 20
x = √20
= 2√5.
So the area of triangle
= 1/2 * base * height
= 1/2 * 2x * x
= x^2
= (2√5)^2
= 20.
