ok about this exercise, we need the square meters measured by the entire stand to do the calculations, because the statement only gives the square meters that are painted with a paint can

5 0

4 years ago

According to a research center, 16% of all merchandise sold in a particular country gets returned. A department store in a certa

Mamont248 [21]

Answer:

a) point estimate of the proportion of items returned for the population of sales transactions at the store in the given city

Point estimate = 0.3

b) The 95% confidence interval for the proportion of returns at the store in the given city

( 0.19958,0.40042)

Step-by-step explanation:

Given the Population proportion 'P'= 16% = 0.16

Given data a department store in a certain city sampled 80 items sold in January and found that 24 of the items were returned

The sample proportion $p = \frac{x}{n}$

here x =24 and n = 80

The sample proportion $p = \frac{x}{n} = \frac{24}{80} = 0.3$

a) Point estimate:-

A point estimate of the true proportion P

Point estimate = $p = \frac{x}{n}$

point estimate of the proportion of items returned for the population of sales transactions at the store in the given city

$p = \frac{x}{n} = \frac{24}{80} = 0.3$

b) The 95% confidence interval for the proportion

The 95% confidence interval for the proportion of returns at the store in the given city

$(p - z_{\alpha } \sqrt{\frac{p(1-p)}{n} } , p + z_{\alpha }\sqrt{\frac{p(1-p)}{n} } )$

substitute all values we get ,

$(0.3 - 1.96 \sqrt{\frac{0.3(1-0.3)}{80} } , 0.3 + 1.96\sqrt{\frac{0.3(1-0.3)}{80} } )$

on simplification, we get

(0.3-0.10042 ,0.3+0.10042)

( 0.19958,0.40042)

Conclusion:-

a) point estimate of the proportion of items returned for the population of sales transactions at the store in the given city

Point estimate = 0.3

b) The 95% confidence interval for the proportion of returns at the store in the given city

( 0.19958,0.40042)

5 0

4 years ago

How many numbers are reciprocal of themselves?

const2013 [10]

Answer:

two: +1 and -1

Step-by-step explanation:

If a number is equal to its own reciprocal, it will satisfy the equation ...

x = 1/x

Multiplying by x and subtracting 1 gives ...

x^2 -1 = 0

This factors as ...

(x -1)(x +1) = 0

By the zero product rule, the solutions are those values of x that make one or more factors zero:

x = 1

x = -1

There are two self-reciprocals.

6 0

3 years ago

The temperature at 9:00 a.m. was 4°C. At 7:00 p.m., the temperature

Verdich [7]

Answer:

16-degree decrease

Step-by-step explanation:

Take the final temperature of -12 and subtract the initial temperature of 4

-12 - 4

-16

The change in temperature is 16 degrees

The minus sign tells us it was a decrease

3 0

3 years ago

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