Answer:
Sample size should be atleast 617
Step-by-step explanation:
given that a 95% confidence interval for the mean of a population is to be constructed and must be accurate to within 0.3 unit.
i.e. margin of error <0.3
Std devition sample = 3.8
For 95% assuming sample size large we can use z critical value
Z critical = 1.96
we have

Sample size should be atleast 617 to get an accurate margin of error 0.3
Count the distance d, which gives you 7.
Use Pythogarean theorem to find c:

Plug in the numbers:

c is 5.
Same thing with g:

g equals 5.66.
Answer:
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It’s going to be 19/3>37>6.08171>6.012