Answer:
115
Step-by-step explanation:
There is a common difference d between consecutive terms, that is
d = 7 - 1 = 13 - 7 = 19 - 13 = 25 - 19 = 6
This indicates the sequence is arithmetic with n th term
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 1 and d = 6 , thus
a₂₀ = 1 + (19 × 6) = 1 + 114 = 115
Answer:
93.19%
Step-by-step explanation:
We have that the mean (m) is equal to 70.4, the standard deviation (sd) 11.1 and the sample size (n) = 140
They ask us for P (x =69)
For this, the first thing is to calculate z, which is given by the following equation:
z = (x - m) / (sd / (n ^ 1/2))
We have all these values, replacing we have:
z = (69 - 70.4) / (11.1 / (140 ^ (1/2)))
z = 1.49
With the normal distribution table (attached), we have that at that value, the probability is:
P (z <1.49) = 0.9319
The probability is 93.19%
