Answer:
Step-by-step explanation:
x-y=14
x-1/3y=1/10
-y=14-x
y=-14+x
take out the factors
x-10/30y=3/30
30x-10y=3
substitute
30x-10(-14+x)=3
30x+140-10x=3-140
20x/20=-137/20
x=-6.85
y=-14+(-6.85)
y=-20.85
Answer:
B
Step-by-step explanation:
The answer is 176 because 86+86=176
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
1 full revolution=360
4seconds=360degrees
how many seconds is 90 degrees
4:360=x:90
4/360=x/90
simpllfiy
1/90=x/90
1=x
answer is 1 second
