If the mean score is 55% and the s.d. is 15%, then a test score of at least
55% + 1.5 × 15% = 77.5%
falls in the A range.
The next cutoff score is 0.5 s.d. from the mean, which is
55% + 0.5 × 15% = 62.5%
so any test score between 62.5% and 77.5% is in the B range.
The next cutoff is
55% - 0.5 × 15% = 47.5%
so a score between 47.5% and 62.5% gets a C.
The lower limit of the next range is
55% - 1.5 × 15% = 32.5%
so 32.5% - 47.5% gets a D.
Anything lower than 32.5% is an F.
Answer:
C≈62.83
Step-by-step explanation:
Use the formula C=πd
Plug in 20 for d and simplify
You then get 62.8318530718 in a calculator
So, you round it to 62.83
A = 1 and b=2 which means 1+2 = 3
Answer:
The Probability = 0.16
Step-by-step explanation:
Empirical rule formula states that:
68% of data falls within 1 standard deviation from the mean - that means between μ - σ and μ + σ.
95% of data falls within 2 standard deviations from the mean - between μ – 2σ and μ + 2σ.
99.7% of data falls within 3 standard deviations from the mean - between μ - 3σ and μ + 3σ.
Average = 13.1 years
Standard deviation = 1.5 years
x = 14.6 years
= 14.6 -13.1/1.5
= 1
This falls within 1 standard deviations of the mean
68% of data falls within 1 standard deviation from the mean - that means between μ - σ and μ + σ.
Hence:
100 - 68%/2 = 32/2 = 16%
Converting to probability = 0.16
The probability of a meerkat living longer than 14.6 years is 0.16
The value of three is three hundred or 300 or 3 x 100
