Plssssss help me ASAP!!!!!

List below are the speeds (mi/h) measured from southbound traffic on I-280 near Cupertino, CA. Use the sample data to construct

zheka24 [161]

Answer:

The 99% confidence interval of the population standard deviation is 1.7047 < σ < 7.485

Step-by-step explanation:

Confidence interval of standard deviation is given as follows;

$\sqrt{\dfrac{\left (n-1 \right )s^{2}}{\chi _{1-\alpha /2}^{}}}< \sigma < \sqrt{\dfrac{\left (n-1 \right )s^{2}}{\chi _{\alpha /2}^{}}}$

s = $\sqrt{\dfrac{\Sigma (x - \bar x)^2}{n - 1} }$

Where:

$\bar x$ = Sample mean

s = Sample standard deviation

n = Sample size = 7

χ = Chi squared value at the given confidence level

$\bar x$ = ∑x/n = (62 + 58 + 58 + 56 + 60 +53 + 58)/7 = 57.857

The sample standard deviation s = $\sqrt{\dfrac{\Sigma (x - \bar x)^2}{n - 1} }$ = 2.854

The test statistic, derived through computation, = ±3.707

Which gives;

$C. I. = 57.857 \pm 3.707 \times \dfrac{2.854}{\sqrt{7} }$

$\sqrt{\dfrac{\left (7-1 \right )2.854^{2}}{16.812}^{}}}< \sigma < \sqrt{\dfrac{\left (7-1 \right )2.854^{2}}{0.872}}$

1.7047 < σ < 7.485

The 99% confidence interval of the population standard deviation = 1.7047 < σ < 7.485.

7 0

3 years ago

Will mark brainliest. will be reported if only for the points

tia_tia [17]

Answer:

d=~7.6

Step-by-step explanation:

7^2+3^2=d^2

49+9=d^2

58=d^2

Square root of 58=~7.6

d=~7.6

6 0

3 years ago

Read 2 more answers

When finding the margin of error for the mean of a normally distributed population from a sample, what is the critical probabili

svlad2 [7]

Critical probability is the essentially cut-off value. The critical probability when the confidence level of 58% is 0.79.

<h3>What is the critical probability?</h3>

Critical probability is the essentially cut-off value that defines the region where the test statistic is unlikely to lie.

As it is given that the confidence level is 58%. therefore, in order to calculate the critical probability, we need to calculate the margin of error within a set of data, and it is given by the formula

$\rm Critical\ Probability, (P*) = 1-\dfrac{\alpha }{2}$

where the value of the α is expressed as,

$\alpha= 1 -\dfrac{\rm Confidence\ interval}{100}$

Now, as the confidence interval is given to us, therefore, the value of the alpha can be written as,

$\alpha= 1 -\dfrac{\rm 58\%}{100} = 0.42$

Further, the critical probability, assuming a confidence level of 58% is,

$\rm Critical\ Probability, (P*) = 1-\dfrac{\alpha }{2}\\\\\rm Critical\ Probability, (P*) = 1-\dfrac{0.42}{2} = 0.79$

Hence, the critical probability is 0.79.

Learn more about Critical Probability:

brainly.com/question/5625386

6 0

2 years ago

A school had 400 girls last year and the number of boys was 95 more than that of the girls. This year the number of girls had in

STatiana [176]

Answer: The fraction by what the number of boys had been reduced=1/11

Step-by-step explanation:

Step 1: To calculate the number of boys last year.

According to the question,

The number of boys last year= 400+95

The number of boys last year=495

Step 2: To calculate the number of girls this year.

According to the question,

The number of girls this year= 400 + 400*1/5

The number of girls this year= 480

Step 3: To calculate the number of boys this year.

According to the question,

The number of boys this year= 480 – 30

The number of boys this year=450

Step 4: To calculate the fraction by what the number of boys had been reduced.

The number of boys reduced= the number of boys last year - the number of boys this year

The number of boys reduced= 495 - 450 = 45

The fraction by what the number of boys had been reduced

= The number of boys reduced/the number of boys last year

Therefore,

The fraction by what the number of boys had been reduced= 45/495= 1/11

6 0

3 years ago

Read 2 more answers

-7c , -6c , -1c , 4c , 0c , 0c , 3c work out the mean temperature

mixas84 [53]

Step-by-step explanation:

(-7)+(-6)+(-1)=-14

(-14)-3=-11

-11÷7=-1.5714285714286 or -2 if you round too the tenths place

7 0

3 years ago