Answer:
n = 10
Explanation:
The nth term of an arithmetic sequence is expressed as:
Tn = a + (n-1)d
a is the first term
n is the number of terms
d is the common difference
Let the sequence be 2, T1, T2, T3...Tn, 46
The common difference is expressed as d = b-a/n+1
T1 = 2 + d
Given b = 46 and a = 2
d = 46-2/n+1
d = 44/n+1
T1 = 2 + (44/n+1)
T1 = 2(n+1)+44/n+1
T1 = 2n+2+44/n+1
T1 = 2n+46/n+1
Similarly;
Tn = 2 + nd
Tn = 2 + n(44/n+1)
Tn = 2 + 44n/n+1
Tn = 2(n+1)+44n/n+1
Tn = (2n+2+44n)/n+1
Tn = 46n+2/n+1
If the ratio of the first mean to last mean is 1:7 then T1/Tn = 1/7
(2n+46/n+1)÷(46n+2/n+1) = 1/7
2n+46/n+1 * n+1/46n+2 = 1/7
2n+46/46n+2 = 1/7
Cross multiply and solve for n:
46n + 2 = 7(2n + 46)
46n + 2 = 14n + 322
46n - 14n = 322-2
32n = 320
n = 320/32
n = 10
Hence the value of n is 10