HELP ASAP!! PLSS HELP !!! ANSWER CORRECTLY PLS

A manufacturer of piston rings for automobile engines frequently tests the width of the rings for quality control. Last week, a

kow [346]

Answer:

II and III

See explanation above

Step-by-step explanation:

When all other rings remain the same, which of the following conditions would have resulted in a wider interval than the one constructed?

I. A sample size of 20 with 95 percent confidence

II. A sample size of 15 with 99 percent of confidence

III. A sample size of 12 with 95 percent confidence

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$

The margin of error is given by:

$ME= t_{\alpha/2}\frac{s}{\sqrt{n}}$

I. A sample size of 20 with 95 percent confidence

The original sample size was 15, the degrees of freedom for the original interval would be n-1=14 , the value for $\alpha=0.05$ and $\alpha/2=0.025$ and then the critical value is $t_{critc}=2.14$

And then the Margin of error would be:

$ME=2.14 \frac{s}{\sqrt{15}}=0.553 s$

For the new sample size n=20 the degrees of freedom for the new interval interval would be n-1=19 , the value for $\alpha=0.05$ and $\alpha/2=0.025$ and then the critical value is $t_{critc}=2.09$

And then the Margin error would be:

$ME=2.09 \frac{s}{\sqrt{20}}=0.467 s$

So then we have a lower margin of error so then we will have a shorter interval

II. A sample size of 15 with 99 percent of confidence

The original sample size was 15, the degrees of freedom for the original interval would be n-1=14 , the value for $\alpha=0.05$ and $\alpha/2=0.025$ and then the critical value is $t_{critc}=2.14$

And then the Margin of error would be:

$ME=2.14 \frac{s}{\sqrt{15}}=0.553 s$

For the new interval the sample size n=15 the degrees of freedom for the new interval interval would be n-1=14 , the value for $\alpha=0.01$ and $\alpha/2=0.005$ and then the critical value is $t_{critc}=2.98$

And then the Margin error would be:

$ME=2.98 \frac{s}{\sqrt{15}}=0.769 s$

So then we have a greater margin of error so then we will have a wider interval. And this makes sense since with more confidence the interval needs to be wider.

III. A sample size of 12 with 95 percent confidence

The original sample size was 15, the degrees of freedom for the original interval would be n-1=14 , the value for $\alpha=0.05$ and $\alpha/2=0.025$ and then the critical value is $t_{critc}=2.14$

And then the Margin of error would be:

$ME=2.14 \frac{s}{\sqrt{15}}=0.553 s$

For the new interval the sample size n=12 the degrees of freedom for the new interval interval would be n-1=11 , the value for $\alpha=0.05$ and $\alpha/2=0.025$ and then the critical value is $t_{critc}=2.20$

And then the Margin error would be:

$ME=2.20 \frac{s}{\sqrt{12}}=0.635 s$

So then we have a greater margin of error so then we will have a wider interval.

5 0

4 years ago

Helpppppppppppppppp!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

adelina 88 [10]

X=119/3 not sure if you have to show your work but if you do the first step is multiply both sides n the rest of the steps are in the photo

4 0

3 years ago

PLZ ANSWER ASAP 100 POINTS AND BRAINLIEST PLZ PLZ HELP

abruzzese [7]

Answer:

Yes one pair of the opposite sides could measure 10 inches , and the other pair could measure 13 inches.

Step-by-step explanation:

A parallelogram have opposite sides parallel and congruent

the given quadrilateral is a parallelogram then

10 = x + 2 Equation A

x + 5 = 2x - 3 Equation B

Solving for Equation A:

x = 10 -2 = 8 inches

Solving for Equation B;

2x - x = 5 + 3

x = 8 inches

Value X are the same equations.

Means that

For x=8 inches opposite side

So Yes one pair of the opposite sides could measure 10 inches , and the other pair could measure 13 inches.

4 0

3 years ago

YOUR TURN

Karolina [17]

Answer:

The equation is: y = 15·x

Step-by-step explanation:

It is provided that at the Speedy Bike Works, 15 bicycles are produced each hour.

Consider the table below.

Number of Hours: 1 3 6 10

Number of Bicycles Produced: 15 45 90 150

Compute the ratio of number of bicycles produced and number of hours for every data above as follows:

$\text{1 hour}=\frac{15}{1}=15:1\\\\\text{3 hour}=\frac{45}{3}=\frac{15}{1}=15:1\\\\\text{6 hour}=\frac{90}{6}=\frac{15}{1}=15:1\\\\\text{10 hour}=\frac{150}{10}=\frac{15}{1}=15:1$