Answer:
(4x+5)(-3x-1) = -12x²-19x-5
Option A:
(-16x² + 10x - 3) + (4x² - 29x - 2) = -12x²-19x-5
Option A is correct.
Option B:
3(x - 5) - 2(6x² + 9x + 5) = -12x²-15x-25
Option B is wrong.
Option C:
2(x - 1) - 3(4x² + 7x + 1) = -12x²-19x-5
Option C is correct.
Option D:
(2x² - 11x - 9) - (14x² + 8x - 4) = -12x²-19x-5
Option D is correct.
What you have to do is add them all!
20 bar
11.4 2 11.4 weights
11.4
4.5 2 4.5 weights
4.5
450.0 4 450 weights
450.0
450.0
+450.0
---------
1.8
10
200
+1,600
--------------
1,811.8 is the answer
Answer:
Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Step-by-step explanation:
We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.
If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.
Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.
<u></u>
<u>SO, Margin of error formula is given by;</u>
Margin of error =
where, = significance level = 10%
= standard deviation = 2.0
n = number of families
Now, in the z table the critical value of x at 5% ( ) level of significance is 1.645.
SO, Margin of error =
0.5 =
n =
= 43.3 ≈ 43
Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Answer:
38.11%
Step-by-step explanation:
Given that:
Mean (μ) = 75, standard deviation (σ) = 5
Z score is a measure in statistics to determine the variation of a raw score from the mean. It is given by the equation:
To calculate the percentage of students scored between a 73 and 78 (C grade), we need to find the z score for 73 and then for 78.
For x = 73, the z score is:
For x = 78, the z score is:
From the probability distribution table:
P(73 < x < 78) = P(-0.4 < z < 0.6) = P(z < 0.6) - P(z < -0.4) = 0.7257 - 0.3446 = 0.3811 = 38.11%
0.75 miles per hour I think....