Answer:
a) First Average mean = 21
b) Current mean = 22
Step-by-step explanation:
Formula For mean =
Sum of Terms/ Number of terms
a)Sandy had test scores of 20, 25, 17, 22, and 21.
Number of terms = 5
Mean = (20 + 25 + 17 + 22 + 21)/5
= 105/5
= 21
b) On the next 3 test Sandy's score were 24, 24, and 23
To calculate this current mean, we will add the first 5 test scores, with this current 3 test scores and then find the average.
Mean = (20+ 25+ 17 +22 +21 + 24 + 24 + 23)/8
Mean = 176/8
Mean = 22
