Answer:
97.5%
Explanation:
By the empirical rule (68-95-99.7),
- 68% of data are within <em>μ </em>- <em>σ</em> and <em>μ </em>+ <em>σ</em>
- 95% of data are within <em>μ </em>- 2<em>σ</em> and <em>μ </em>+ 2<em>σ</em>
- 99.7% of data are within <em>μ </em>- 3<em>σ</em> and <em>μ </em>+ 2<em>σ</em>
<em>σ </em> and <em>μ</em> are the standard deviation and the mean respectively.
From the question,
<em>μ</em> = 7.2 cm
<em>σ</em> = 0.38 cm
7.96 = 7.2 + (<em>n</em> × 0.38)
<em>n</em> = 2
Hence, 7.96 represents <em>μ </em>+ 2<em>σ</em>.
P(X < <em>μ </em>+ 2<em>σ</em>) = P(X < <em>μ</em>) + P(<em>μ</em> < X < <em>μ </em>+ 2<em>σ</em>)
P(X < <em>μ</em>) is the percentage less than the mean = 50%.
P(<em>μ</em> < X < <em>μ </em>+ 2<em>σ</em>) is half of P(<em>μ </em>- 2<em>σ</em> < X < <em>μ </em>+ 2<em>σ</em>) = 95% ÷ 2 = 47.5%.
Considering this, for apples that are no more than 7.96 cm,
P(X < 7.96) = P(X < 7.2) + P(7.2 < X < 7.96) = 50% + 47.5% = 97.5%
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It can't. Waves must have a medium to travel through
Answer:
Explanation:
frequency of sound waves = 688 Hz
wavelength = 344 / 688 = .5 m
The problem is based on interference of sound waves
For the observer , path difference of sound waves reaching his ear
= 3.5 - 3.00
.5 m
= wavelength
Path difference is equal to wavelength so there will be constructive interference and hence louder sound will be heard by the listener than normal sound as sound waves interfere constructively.
Here we have been given two charged body W and X.
We are asked to determine the nature of charge.
Before coming into conclusion, first we have to understand the electric field lines.
The electric field lines are pictorial representation of imaginary lines which are drawn to denote the electric field in a graphical way.
The electric field line starts from a positive charge and ends at a negative charge.It means for positive charges the electric field lines are outward and for negative charges the filed lines will be inward.
In the given diagram,the filed lines for W is towards W itself.The same is also in case of X.
Hence both the charges must be negative in nature.
Hence the correct answer to the question will be B i.e W negative and X: NEGATIVE.
Answer:
3 in front means the no.of NH4 atoms
Hope it is correct ^_^
