ILL GIVE BRAINLIEST! PLEASE HELP I DONT UNDERSTAND!
1 answer:
Answer:
S₁₅ = 645
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
=
[ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Using the nth term formula = 5n + 3 , then
a₁ = 5(1) + 3 = 5 + 3 = 8
a₂ = 5(2) + 3 = 10 + 3 = 13 , then
d = a₂ - a₁ = 13 - 8 = 5
Thus
S₁₅ = [ (2 × 8) + (14 × 5) ]
= 7.5( 16 + 70)
= 7.5 × 86
= 645
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Answer:
Her height, in inches, is closest to 70.
Step-by-step explanation:
This can be solved by the the z-score formula:
On a normaly distributed set with mean and standard deviation
, the z-score of a value X is given by:
Each z-score value has an equivalent p-value, that represents the percentile that the value X is:
In this problem, we have that:
A z-score of 2.33 has a p-value of 0.9901. This means that a height with a z-score of 2.33 is in the 99th percentile.
So, what is the value of X when
Her height, in inches, is closest to 70.