Answer:

Step-by-step explanation:
-The margin of error is calculated using the formula:

-We substitute the values, n=900 and ME=30 in the formula to solve for standard deviation:

Hence, the population standard deviation is 547.1125
Answer:
Beatrice will accumulate $1230.72 at the end of the year.
Step-by-step explanation:
We can write:

for deposits
The first month would have only the deposit reflected in her balance, then, expanding some steps of the calculation would yield:

A geometric series is given by:

Translating our series to the short form:

plugin in the values for the 12 month gives:

Momentum is mass times velocity so the answer is 48kgm/s
Answer:
Obtuse
Step-by-step explanation:
The sum of squares of the short sides is 130, so is less than the square of the long side. The long side (12) is longer than it would need to be for a right triangle, so the largest angle is bigger than 90°.
The triangle is obtuse.
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A triangle solver app or calculator can confirm this. Note angle C is about 96°, an obtuse angle.