Answer:
= 1+2n and 63
Step-by-step explanation:
the question belongs to arithmetic sequence and
can be determined by the formula
= a1 + d (n-1)
Let "
" represents the number of band members in the nth row
and 'd' represents the common difference.( as stated each row has 2 more band members than the row before it)
therefore, d=2
'a1' represents first row that has three members. So, a1 = 3
->Rule for nth term will be:
= 3 + 2(n-1)
= 3 + 2n -2
= 1+2n
-> In order to find total number of band members '
'
Let
represent total number in n rows
We'll use the formula, i.e
= n/1 (
+
)
where, n is the number of terms,
is the first term and
is the last term
So,
n=7
= 1 + 2(7)= 15
=>
= 7/2 (3 + 15)
= 63
The total number of band members are 63
Answer:
2.28%
Step-by-step explanation:
Mr. bowens test is normally distributed with a mean (μ) of 75 and a standard deviation (σ) of 3 points.
The z score is used in probability to show how many standard deviation is a raw score below or above the mean. The formula for the z score (z) is given by:

For a raw score (x) of 81 points, the z score can be calculated by:

Therefore from the normal probability distribution table, the probability that a randomly selected score is greater than 81 can be given as:
P(x > 81) = P(z > 2) = 1 - P(z < 2) = 1 - 0.9772 = 0.0228 = 2.28%
No, this is not true, 22+32 =54 this is not a true statement