Brett wants to paint the exterior of his two-story home but does not know what length ladder he should buy. The top of his roof
is 29 ft above ground level, and (for safety reasons) the ladder should not be at more than an 80° angle from the ground. How long, rounded up to the nearest foot, is the shortest ladder that Brett should buy?
2 answers:
Answer:
Brett should buy a ladder of minimum 30 ft length.
Step-by-step explanation:
Brett wants to paint his exterior of a double story home.
Height of the roof of the second story from the ground = 29 feet
Maximum angle between the ground and the ladder should be = 80°
Now from the figure,
sin 80° =
0.9848 =
AC =
AC = 29.45
≈ 30 ft
Therefore, Brett should buy a ladder of minimum 30 ft length.
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Answer:
a) Null and alternative hypothesis
b) Test statistic t=-1.565
P-value = 0.0612
NOTE: the sample size is n=65.
c) Do not reject H0. We cannot conclude that the price in Providence for a bottle of red wine that scores 4.0 or higher on the Vivino Rating System is less than the population mean of $32.48.
d) Null and alternative hypothesis
Test statistic t=-1.565
Critical value tc=-1.669
t>tc --> Do not reject H0
Do not reject H0. We cannot conclude that the price in Providence for a bottle of red wine that scores 4.0 or higher on the Vivino Rating System is less than the population mean of $32.48.
Step-by-step explanation:
This is a hypothesis test for the population mean.
The claim is that the mean price in Providence for a bottle of red wine that scores 4.0 or higher on the Vivino Rating System is less than the population mean of $32.48.
Then, the null and alternative hypothesis are:
The significance level is 0.05.
The sample has a size n=65.
The sample mean is M=30.15.
As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=12.
The estimated standard error of the mean is computed using the formula:
Then, we can calculate the t-statistic as:
The degrees of freedom for this sample size are:
This test is a left-tailed test, with 64 degrees of freedom and t=-1.565, so the P-value for this test is calculated as (using a t-table):
As the P-value (0.0612) is bigger than the significance level (0.05), the effect is not significant.
The null hypothesis failed to be rejected.
At a significance level of 0.05, there is not enough evidence to support the claim that the mean price in Providence for a bottle of red wine that scores 4.0 or higher on the Vivino Rating System is less than the population mean of $32.48.
<u>Critical value approach</u>
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At a significance level of 0.05, for a left-tailed test, with 64 degrees of freedom, the critical value is t=-1.669.
As the test statistic is greater than the critical value, it falls in the acceptance region.
The null hypothesis failed to be rejected.
Check the picture below.
since we know that x = 3/7, we can then plug that on either of the twin legs, since it's an isosceles, and get the length of each leg, so say let's plug it in 5x + 16
