Using the Empirical Rule, it is found that her finishing time will be between 70 and 82 seconds in 95% of her races.
<h3>What does the Empirical Rule state?</h3>
It states that, for a normally distributed random variable:
- Approximately 68% of the measures are within 1 standard deviation of the mean.
- Approximately 95% of the measures are within 2 standard deviations of the mean.
- Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, the mean is of 76 seconds and the standard deviation is of 3 seconds, then:
76 - 2 x 3 = 70.
76 + 2 x 3 = 82.
Which means that values between 70 and 82 seconds are within 2 standard deviations of the mean, hence the percentage is of 95%.
More can be learned about the Empirical Rule at brainly.com/question/24537145
Answer:
1/6
Step-by-step explanation:
after step 2, you simplify
Answer:
<h2>a)
483.6cm²</h2><h2>b)
850.1 cm³</h2>
Step-by-step explanation:
Given the slant height 's' and its radius 'r' to be 15cm and 8cm respectively.
the total surface of the cone A = πrs+πr² and the volume is expressed as
V = 1/3πr²h
For the surface area of the cone;
Given parameters
radius = 8 cm and slant height s = 15 cm
Total surface area A = π(8)(15) + π(8)²
A = 90π+64π
A = 154π
If π = 3.14
A = 154(3.14)
A = 483.56cm²
A = 483.6cm²
Hence the total surface area of the cone to the nearest tenth is 483.6cm²
For the volume of the cone;
V = 1/3πr²h
Using pythagoras theorem to get the height of the cone;
l² = h²+r²
h² = l²-r²
h² = 15²-8²
h² = 225-64
h² = 161
h = √161
h = 12.69cm
V = 1/3π* (8)² * 12.69
V = 1/3π* 64 * 12.69
V = 1/3*3.14* 64 * 12.69
V = 2550.1824/3
V = 850.06 cm³
V = 850.1 cm³
Hence, the volume of the cone is 850.1 cm³ to the nearest tenth.
