Do you know the answer?

A scientist wishes to estimate the mean breaking strength of a certain type of steel rod within 3.0 psi with 95% confidence. Bas

yaroslaw [1]

Answer:97 rods

Step-by-step explanation:

The number of steel rods for 95% confidence level

$n=\left ( \frac{Z_\frac{\alpha }{2}\times \hat{\sigma }}{E} \right )^2$

$Z_\frac{\alpha }{2}=1.96$

E=3

$\hat{\sigma }=15$

Substituting values

$n=\left ( \frac{1.96\times 15}{3}\right )^2$

$n=96.04\approx 97$

Thus 97 rods is tested

6 0

3 years ago

Which statements describe a residual plot for a line of best fit that is a good model for a scatterplot? Check all that apply. T

lidiya [134]

Answer:

The points are randomly scattered with no clear pattern

The number of points is equal to those in the scatterplot.

Step-by-step explanation:

The points in the residual plot of the line of best fit that is a good model for a scatterplot are randomly scattered with no clear pattern (like a line or a curve).

The number of points in the residual plot is always equal to those in the scatterplot.

It doesn't matter if there are about the same number of points above the x-axis as below it, in the residual plot.

The y-coordinates of the points are not the same as the points in the scatterplot.

8 0

2 years ago

Read 2 more answers

Molly, a purchasing agent for a high-tech firm, is ordering computers for a new branch office. Laptops cost $540 apiece and desk

NISA [10]

Answer:

540x+680y<=20000

Step-by-step explanation:

x will be the number of laptops. Since they are $540 each, 540x is the amount spent on laptops, depending on how many (x) are purchased.

y will be the number if desktops. Since they are $680 each, 680y is the amount spent on desktops, depending on how many (y) are purchased.

Adding all the money spent on laptops and desktops, we get

540x + 680y. This amount must be less than the $20000. It can be exactly $20000 also. But it cannot be more than $20000.

540x+680y<=20000

3 0

2 years ago

A parabola has a vertex at (4, 0) and passes through the point (6, 1). Which of the following is the equation of this parabola i

Doss [256]

Easy

y=a(x-h)^2+k
vertex is (h,k)
we know that vertex is (4,0)
input that point for (h,k)
y=a(x-4)^2+0
y=a(x-4)^2
passes thorugh the point (6,1)
input that point to find a
1=a(6-4)^2
1=a(2)^2
1=a(4)
divide both sides by 4
1/4=a

thefor the equation is
y=(1/4)(x-4)^2
or
y=(1/4)x^2-2x+4

7 0

3 years ago

The null hypothesis claims that the proportion of community college students who work full-time is 0. 45. The alternative hypoth

diamong [38]

The stronger the evidence is against the null hypothesis, the higher the divergence from it.

What do you mean by null hypothesis ?

A statistical hypothesis known as a null hypothesis asserts that no statistical significance can be found in a collection of provided observations. Using sample data, hypothesis testing is performed to judge a theory' veracity. It is sometimes referred to as just "the null," and its symbol is $H_{0}$ . To determine if a theory regarding markets, investing methods, or economies is correct or wrong, quantitative analysts employ the null hypothesis,

The null hypothesis states that the percentage of the population who works full time is 0.45.

As a result, 450 persons who are randomly selected from a population of 1000 work full-time.

A different hypothesis states that the ratio is higher than 0.45.

In the options provided, the proportion for the first option is 300/1000, or 0.3.

In the second choice, 500/1000 equals 0.5

Third alternative: 700/1000 = 0.7

Therefore, the stronger the evidence is against the null hypothesis, the higher the divergence from it.

To learn more about the null hypothesis from the given link.

brainly.com/question/15980493

#SPJ4

4 0

11 months ago