Answer:
Weight of mixing water=224.541 lb
Step-by-step explanation:
Taking 1 cubic yard of concrete
Mass of gravel = 2314 lb
Moisture content = 3.5% Absorption 4.2%
Extra water needed = (4.2-3.5)*2314/100= 16.198 lb
Mass of sand= 899 lb
Moisture content = 5.7% Absorption =1.4%
Water released = (5.7-1.4)*899/100= 38.657 lb
Free water = 244 lb
Weight of mixing water = free water + extra water needed-water released = 244+16.198-38.657=224.541 lb
Weight of mixing water=224.541 lb
Answer:
99.72% probability that the proportion of Grammy award winners will differ from the singers proportion by less than 5%.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
When the distribution is normal, we use the z-score formula.
In a set with mean and standard deviation , the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean and standard deviation , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation .
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean and standard deviation
In this question:
So
What is the probability that the proportion of Grammy award winners will differ from the singers proportion by less than 5%?
This is the pvalue of Z when X = 0.41 + 0.05 = 0.46 subtracted by the pvalue of Z when X = 0.41 - 0.05 = 0.36. So
X = 0.46
By the Central Limit Theorem
has a pvalue of 0.9986
X = 0.36
has a pvalue of 0.0014
0.9986 - 0.0014 = 0.9972
99.72% probability that the proportion of Grammy award winners will differ from the singers proportion by less than 5%.
Answer:
89
Step-by-step explanation:
Answer:
y = -7/5x - 6.7
Step-by-step
y = -7/5x + 6. A Line that is parallel will always have the same slope. The slope is m. m in this situation = -7/5x. A lines equation is y = mx + b. m = -7/5. y = -7/5x + b. Now to find b we can substitute the given point which goes through the new line, (2, -6). In this point x =2 and y = -6. Now substitute the x and y values into our equation. y = -7/5x + b is now -6 = -7/5(2) + b. -7/5(2) = -7/10. -6 = 7/10 + b. Subtract 7/10 from -6. Its -6 and 7/10 or -6.7 . -6.7 = b. b = -6.7. Now substitute the b value into the equation. y = -7/5x -6.7.
A. y = (-5/2)x - 3
B. y = (-2/5)x + 3
C. y = (-2/5)x - 3
D. y = (2/5)x + 3
Answer:
B
Step-by-step explanation:
The equation we must find is in y = mx + b form. We are given that it intercepts (0,3), so the y-intercept it 3 and b = 3. We can find the slope with the two points we are given: m = (3-5)/(0(-5)) = -2/5. Substituting these values, we find: y = (-2/5)x + 3