Syntax errors/typos in rct_vaccines.ipynb

[shreysrins]

1. In the first code cell,

outcome_controls =115/num_controls

should be outcome_controlled to match later code.

2. In the first code cell,

std_treatment_effect = np.sqrt(var_treatment_effect

is missing the right parenthesis.

3. In the first code cell,

print(f"95 % confidence interval is [{CI_delta[0])}, {CI_delta[1]}]")

has an extra parenthesis after CI_delta[0].

4. In the Pfizer/BNTX Covid-19 RCT markdown cell, "averal" is written instead of "overall."

5. In the cell below, "vaccie" is written instead of "vaccine."