Its not 70 its 56, because you have to see how many minutes it takes for 1 to do 4 walls which would be 40*8.
Then you have to see if how many minutes its take a person to do one wall which is 8*40/4 from getting the amount of the 1 person doing 4 walls and get 80.
Then you need to see how many walls a person can paint 7 walls out of 10 people.So, we know how many minutes for each wall which is 80 and then multiply it by 7 to get 560 and divide it by 10 to get a product of 56.
We are given frequency distribution in the question
to find the probability distribution from frequency distribution we need to divide frequency by total number of observations.
Here, total number of observations are 6+10+7+5=28
so , we will have probability distribution table as
X 0 1 2 3
P(x) .21 .35 .25 .17
probability distributiuon describes all possible values that a random variable can take within a given range.
frequency distribution is the presentation that presents number of observation in given interval.
Solution:
Vertical angles are a pair of opposite angles formed by intersecting lines. re vertical angles. Vertical angles are always congruent.
These two angles (140° and 40°) are Supplementary Angles because they add up to 180°:
Notice that together they make a straight angle.
Hence,
From the image
The following pairs form vertical angles

Hence,
One pair of the vertical angles is ∠1 and ∠3
Part B:
Two angles are said to be supplementary when they ad together to give 180°
Hence,
From the image,
The following pairs are supplementary angles

Hence,
One pair of supplementary angles is ∠5 and ∠6
Answer:
B is True
A, C. D are false
Step-by-step explanation:
Given :
Sample size, n = 120
Mean diameter, m = 10
Standard deviation, s = 0.24
Confidence level, Zcritical ; Z0.05/2 = Z0.025 = 1.96
The confidence interval represents how the true mean value compares to a set of values around the mean computed from a set of sample drawn from the population.
The population here is N = 10000
To obtain
Confidence interval (C. I) :
Mean ± margin of error
Margin of Error = Zcritical * s/sqrt(n)
Margin of Error = 1.96 * 0.24/sqrt(120)
Confidence interval for the 10,000 ball bearing :
10 ± 1.96 * (0.24) / sqrt(120)
Hence. The confidence interval defined as :
10 ± 1.96 * (0.24) / sqrt(120) is the 95% confidence interval for the mean diameter of the 10,000 bearings in the box.
If y = cos(kt), then its first two derivatives are
y' = -k sin(kt)
y'' = -k² cos(kt)
Substituting y and y'' into 49y'' = -16y gives
-49k² cos(kt) = -15 cos(kt)
⇒ 49k² = 15
⇒ k² = 15/49
⇒ k = ±√15/7
Note that both values of k give the same solution y = cos(√15/7 t) since cosine is even.