Can y’all help me with this one (2x-3)(4x+5)=

Complete parts (a) and (b) using the probability distribution below.

katen-ka-za [31]

Μ = (0×0.026) + (1×0.072) +(2×0.152) + (3×0.303) + (4×0.215) + (5×0.164) + (6×0.066)
μ = 0 + 0.072 + 0.304 + 0.909 + 0.86 + 0.82 + 0.396
μ = 3.361 ≈ 3.4

We need the value of ∑X² to work out the variance
∑X² = (0²×0.026) + (1²×0.072) + (2²×0.152) + (3²×0.303) + (4²×0.215) + (5²×0.164) + (6²×0.066)
∑X² = 0+0.072+0.608+2.727+3.44+4.1+2.376
∑X² = 13.323

Variance = ∑X² - μ²
Variance = 13.323 - (3.4)² = 1.763 ≈ 2

Standard Deviation = √Variance = √1.8 = 1.3416... ≈ 1.4

The correct answer related to the value of mean and standard deviation is the option D

An employee works an average of 3.4 overtime hours per week with a standard deviation of approximately 1.4 hours.

7 0

3 years ago

When an object falls freely, the formula for the distance it falls is d= 4.9t^2 where d is

german

Answer:

a) 122.5 m ; b) 10 s

Step-by-step explanation:

Just use the given equation and plug in what you know.

a)

d = 4.9t^2

d = 4.9(5^2)

d = 4.9 * 25

d = 122.5 m

b)

d = 4.9t^2

490 = 4.9t^2

100 = t^2

t = 10 s

3 0

2 years ago

Read 2 more answers

What is the vertex of a graph

densk [106]

It’s the point where the parabola crosses its axis of symmetry

7 0

3 years ago

Read 2 more answers

phyllis invested 66000 dollars, a portion earning simple interest rate of 5% per year and the rest earning a rate of 7% per year

Lelechka [254]

Answer:

Physliis invested 32000 dollar at 5% interest rate and 34000 dollar at 7% interest rate.

Solution:

Let Phyllis invest ‘x’ dollar at 5% per year and (66000-x) dollar at 7% per year.

We know,

$\text { Simple interest }=\frac{\text {Principal} \times r a t e \times T i m e}{100}$

In the question it is given that Simple interest earned from both the investments at the end of the year is $3980.

Using the given below equation, we will try to find out the investments at each rate.

$\begin{array}{l}{\frac{x \times 5 \times 1}{100}+\frac{(66000-x) \times 7 \times 1}{100}=3980} \\\\ {\frac{5 x}{100}+\frac{462000-7 x}{100}=3980} \\\\ {\frac{5 x+462000-7 x}{100}=3980} \\\\ {-2 \mathrm{x}+462000=3980 \times 100} \\\\ {-2 \mathrm{x}=398000-462000} \\\\ {-2 \mathrm{x}=-64000} \\\\ {\mathrm{x}=\frac{-64000}{-2}}\end{array}$

x = 32000

We can calculate amount for 7% interest rate by,

(66000-32000) =34000

Thus Phyllis invested 32000 dollar at 5% interest rate and 34000 dollar at 7% interest rate.

8 0

3 years ago

The following quote is from a paper on the weight of the bottle as a possible extrinsic cue with which to estimate the price (an

yuradex [85]

Answer:

1. a. Weak

2. r^2=0.0169

The variation in the price of the wine explained by the variation in the weight of the bottle is 1.69%.

Step-by-step explanation:

The correlation between the weight of the wine bottles and the price of the wine is r=0.13.

The values for r goes from r=-1, where a perfect negative correlation to r=1 for a perfect positive correlation. The value r=0 indicates no correlation at all.

Then, a value of r close to 0 indicates very weak correlation between the two variables.

The value for r^2 in this case is:

$r^2=0.13^2=0.0169$

The value of r2 can be interpreted as the proportion of the variation in the dependant variable explained by the independent vairable. In this case, the variation in the price of the wine explained by the variation in the weight of the bottle is 1.69%, which is very close to 0.

8 0

2 years ago