Step-by-step explanation:
Count the number of times you have to move the decimal point to the right until it is to the right of the 1st nonzero number.
a) You have to move the decimal point 11 times until it gets to the right of the 1st nonzero number, which is 7. You then rewrite this number as

The exponent of 10 is a negative number because you moved the decimal point to the right.
b) Similarly, you have to move the point 9 times to the right so the answer is

The formula to find the surface area of a circle is: pi x radius², so if we square the radius the answer would be 25, then we multiply that by 3.14 and the answer would be around 78.5, so the answer is 78.5.
The probability that a randomly selected chocolate bar will have between 200 and 220 calories is 3.97%
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more variables and numbers.
The zscore is given a:
z = (raw score - mean) / standard deviation
mean = 225, standard deviation o = 10.
a) For x = 200:
z = (200 - 225) / 200 = -0.125
For x = 220:
z = (220 - 225) / 200 = -0.025
P(-0.125 < z < -0.025) = P(z < -0.025) - P(z < -0.125) = 0.4880 - 0.4483 = 3.97%
b) For x = 190:
z = (190 - 225) / 200 = -0.175
P(z < -0.025) = P(z < -0.175) = 0.4286
The probability that a randomly selected chocolate bar will have between 200 and 220 calories is 3.97%
Find out more on equation at: brainly.com/question/2972832
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