Answer:
a) 16%
b) 2.5%
Step-by-step explanation:
a)
The mean is 70 with standard deviation(SD) of 3 and you are asked to find out the percentage of staff that have <67(70-3 inch= mean - 1 SD) inch size, which means 1 SD below the mean (<-1 SD). Using 68-95-99.7 rule, you can know that 68% of the population is inside 1 SD range from the mean ( -1 SD to + 1 SD).
To put it on another perspective, there are 32% of the population that have < -1 SD and > +1 SD value. Assuming the distribution is symmetrical, then the value of < - 1 SD alone is 32%/2= 16%
b)
The question asks how many populations have size >76 inches, or mean + 2 SD (70+3*2 inch).
You can also solve this using 68-95-99.7 rule, but you take 95% value as the question asking for 2 SD instead. Since 95% of population is inside 2 SD range from the mean ( -2 SD to + 2 SD), so there are 5% of population that have < -2 SD and > +2 SD value. Assuming the distribution is symmetrical, then the value of > +2 SD alone is 5%/2= 2.5%
Your mistake was in this part 9 x 1/100 . After the decimal point the place value starts with tenths so you should write 9 x 1/10 .
Place values
Before the decimal
point
3 ones = 3 x 1
0 tens = 0 x 10
1 hundreds = 1 x 100
After the decimal
point
9 tenths = 9 x 1/10
0 hundredths = 0 x 1/100
3 thousandths= 3 x 1/1000
1 x 100 + 0 x 10 + 3 x 1 + 9 x 1/10 + 0 x 1/100 + 3 x 1/1000
100 + 0 + 3 + 0.9 + 0 + 0.003
100 + 3 +
0.9 + 0.003 = 103.903
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Answer: Any equation that has a -5 before the x will have the same slope. Some examples could be:
y= -5x
y = -5x + 100
y = -5x - 3
Find the Least Common Multiple<span> of the </span>denominators<span> (which is called the Least </span>Common Denominator<span>). Change each fraction (using equivalent fractions) to make their </span>denominators<span> the </span>same<span> as the least </span>common denominator<span>. Then add (or subtract) the fractions, as we wish!</span>