Answer:
The variance of the temperatures of the 10 day period must be at least zero.
Step-by-step explanation:
The variance is the expectation of the squared deviation of a random variable from its mean. It measures how far a set of numbers are spread out from their average value.
Its unit of measure corresponding to the square of the unit of measure of the variable. In this case, the variance of the temperatures is expressed in (°C)². The variance has a minimum value of 0.
Since the variance is squared, it will always have values greater than zero.

I'm not sure why ± that sybol isn't working
all together you can write

Ughh just ignore the "A" symbol .-.
L = rc
= 26.9 * 9*3.14 / 5
= 152.04 to nearest 1/100
To express a decimal number (with a finite decimal expression) in a fraction, you work like this: the numerator is the number without decimale separator (you simply pretend it's not there), while the denominator will be
, where n is the number of digits after the decimal separator.
So, in your case, the number without decimal separator is 53, and you have two digits after the decimal separator, so the fraction will be
which is irreducible.