solve for "l" to find its length
Twenty nine minus eight times a number is equal to five. What is the number?
2 answers:
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solve for "l" to find its length
Answer:
Yes, there enough evidence to reject the claim.
Step-by-step explanation:
Here we need to perform a test for single mean to determine whether the mean cost of raising a child from birth to age 2 by husband-wife families in the U.S. is $13,960.
The hypothesis is:
<em>H₀</em>: The mean cost of raising a child from birth to age 2 by husband-wife families in the U.S. is $13,960, i.e. µ = $13,960.
<em>Hₐ</em>: The mean cost of raising a child from birth to age 2 by husband-wife families in the U.S. is different from $13,960, i.e. µ ≠ $13,960.
The information provided is:
The test statistic is:
The test statistic value is -2.24.
Compute the <em>p</em>-value for this test statistic value at 10% level of significance as follows:
Use the <em>z</em>-table.
The calculated <em>p</em>-value is, 0.0251 < 0.10, therefore the null hypothesis will be rejected.
<u>Conclusion</u>:
As the null hypothesis is rejected at 10% level of significance it can be concluded that there enough evidence to reject the claim.
The mean cost of raising a child from birth to age 2 by husband-wife families in the U.S. is different from $13,960.
Answer:
Speed of the plane in still air: .
Windspeed: .
Step-by-step explanation:
Assume that is the speed of the plane in still air, and that
is the speed of the wind.
- When the plane is travelling against wind, the ground speed of this plane (speed of the plane relative to the ground) would be
.
- When this plane is travelling in the same direction as the wind, the ground speed of this plane would be
.
The question states that when going against the wind (,) the plane travels
in
. Hence,
.
Similarly, since the plane travels in
when travelling in the same direction as the wind (
,)
.
Add the two equations to eliminate . Subtract the second equation from the first to eliminate
. Solve this system of equations for
and
:
and
.
Hence, the speed of this plane in still air would be , whereas the speed of the wind would be
.