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
Answer:
x = -1
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
Step-by-step explanation:
<u>Step 1: Define</u>
0 = 4x + 4
<u>Step 2: Solve for </u><em><u>x</u></em>
- Subtract 4 on both sides: -4 = 4x
- Divide 4 on both sides: -1 = x
- Rewrite: x = -1
Answer:
Give brainliest please! The answer is 53.2 mph
Step-by-step explanation:
Mara's family travels 239.4 miles between the hours of 9:10 a.m. to 1:40 p.m.
1:40 p.m. is 13:40.
Thus, they traveled for
13 hours 40 minutes - 9 hours 10 minutes = 4 hours 30 minutes
that is hours.
Use formula:
where
D = distance
r = rate
t = time.
In your case,
D = 239.4 miles
t = 4.5 hours
He bought 20 pounds of pet food
