Hi! I believe it’s D but not 100% sure- HOPE IT HELPS
Answer:
The correct option is d
Step-by-step explanation:
From the question we are told that
The sample size is n = 64
The mean is 
The standard deviation is 
Generally the standard error of the mean is mathematically represented as

=> 
=> 
Answer:
complementary
Step-by-step explanation
Im not positive but theres a high chance its B
Hey there!
9:19
This is because there are 19 total people taking dance lessons - 9 + 10 - and there are 9 girls taking dance lessons, so the ratio is girls to total students, or 9:19
Hope it helps and have a great day!
B is incorrect which means it is the answer