Answer: C. The size of a business is ordinal-scaled because it has values that can be used as an order or rank of a categorical variable.
Step-by-step explanation: Ordinal variables are simply categorical in nature just like nominal variables, however, the difference exists in the fact that ordinal labels posses an ordered rank or level unlike nominal variables. Though the extent or width of the difference between these labels cannot be ascertained. In the scenario above, size of businesses are labeled qualitatively with labels such as : small, medium and large. This labels depicts and follow a certain order with small being the least, then medium, then large. Telling us large businesses are superior in size to small and medium and medium is superior to large. Though the extent of the difference cannot be accurately ascertained.
The 68-95-99.7 rule tells us 68% of the probability is between -1 standard deviation and +1 standard deviation from the mean. So we expect 75% corresponds to slightly more than 1 standard deviation.
Usually the unit normal tables don't report the area between -σ and σ but instead a cumulative probability, the area between -∞ and σ. 75% corresponds to 37.5% in each half so a cumulative probability of 50%+37.5%=87.5%. We look that up in the normal table and get σ=1.15.
So we expect 75% of normally distributed data to fall within μ-1.15σ and μ+1.15σ
That's 288.6 - 1.15(21.2) to 288.6 + 1.15(21.2)
Answer: 264.22 to 312.98
Step-by-step explanation:
Morning is 4 hr 15 min
afternoon is 4 hour 15 min
together is 8 hour 30 min
8.5*14 = 119 dollars
Answer:
option B.
About 16% of the books have fewer than 150 pages
Step-by-step explanation:
Since we are dealing with a normal distribution
68.27% of the values will fall in the range with the standard deviation
(180-30 , 180+30) = (150, 210)
Approximately 15.86% of the values will be higher than 210
and the rest 15.86% will be lower than 150
So the correct answer is option B.
About 16% of the books have fewer than 150 pages
T = 0
=> Q = 0
t = x
=> Q = arcsin(x/a)
rest it just simple integration of trigonometric function
