All categories

1 year ago

The receipt below shows the money, in dollars, spent by a customer at the Good Groceries store.

Mathematics

2 answers:

sveticcg [70]1 year ago

4 0

Answer:

C: Good Groceries charges 1.20 per kilogram of lettuce.

Step-by-step explanation:

TRUST MEE!!! PLS GIVE ME 5 STARS AND A THANKS!!!! <3

FOLLOW ME ON INSTAGRAM : @a.adrii.ana

Charra [1.4K]1 year ago

4 0

Answer:

C-Good Groceries charges 1.20 dollars per kilogram of lettuce.

Step-by-step explanation:

Plz trust me, got it from khan

Also, follow me on insta; emventures666

<em>Plz give a sis a Brainliest-</em>

You might be interested in

The volume of a fish tank is given by the function V(x)=(x+7)(x-4)(x+3). Write a function describing a fish tank that has the sa

Aleksandr [31]

Answer:

V(x)=(x+9) * (x-4) * (x+6)

Step-by-step explanation:

A fish tank is normally in the shape of a rectangular prism. The volume of a rectangular prism can be calculated using the following formula

V = w * h * l

where w represents the width, h represents the heigh, l represents the length, and V represents the volume of the rectangular prism/fish tank. Therefore, we can use the function provided in the question and simply add 3 units to the length and 2 units to the width in order for it to work for our new fish tank.

V(x)=(x+9) * (x-4) * (x+6)

3 0

2 years ago

A cake has a mass of 2.5kg. It contains 275g of fruit. What percentage of fruit is there in the cake

Travka [436]

The answer is: "11 %" .
__________________________________
There is 11% of fruit in the cake.
______________________________
Explanation:
____________________________________

275g is what percent of 2.5 kg?

First, convert "275 g" into "kg".

Note the exact conversion: 1000 g = 1 kg .

So 275 g = (275/1000) kg = 0.275 kg .

0.275 kg = (n/100) * 2.5 kg ;

→ (n/100) * 2.5 = 0.275 ;
____________________________
Divide each side by "(2.5)"
______________________
→ (n/100) = (0.275) / (2.5) ;

→ (n/100) = 0.11 ;

Multiply each side by "100" ;

n = 11 .
________________________________________
The answer is: 11 % .
________________________________________

8 0

2 years ago

Read 2 more answers

On your birthday you receive a new TV valued at $1199. The value of the TV decreases by 25% each year. What will its value be 4

earnstyle [38]

Answer: 74.93

Step-by-step explanation: if you heard of the line equals line method this should be able to help you.

299.75 25%

---------------=------------------

$1199 100%

so you cross multiply 1199 and 25 and then divide it by 100. which would be 299.75 that is the price per 1 year then you divide that value by 4 and that will be your answer.

299.75 divided by 4= 74.93

hope this helps

4 0

1 year ago

It is believed that as many as 23% of adults over 50 never graduated from high school. We wish to see if this percentage is the

JulijaS [17]

Answer:

1) n=48

2) n=298

3) n=426

Step-by-step explanation:

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".

$p$ represent the real population proportion of interest

$\hat p$ represent the estimated proportion for the sample

n is the sample size required (variable of interest)

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

Part 1

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by $\alpha=1-0.90=0.10$ and $\alpha/2 =0.05$ . And the critical value would be given by:

$z_{\alpha/2}=-1.64, z_{1-\alpha/2}=1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.1$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

We can assume that the estimated proportion is 0.23 for the 25 to 30 group. And replacing into equation (b) the values from part a we got:

$n=\frac{0.23(1-0.23)}{(\frac{0.1}{1.64})^2}=47.63$

And rounded up we have that n=48

Part 2

The margin of error on this case changes to 0.04 so if we use the same formula but changing the value for ME we got:

$n=\frac{0.23(1-0.23)}{(\frac{0.04}{1.64})^2}=297.7$

And rounded up we have that n=298

Part 3

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.04$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

We can assume that the estimated proportion is 0.23 for the 25 to 30 group. And replacing into equation (b) the values from part a we got:

$n=\frac{0.23(1-0.23)}{(\frac{0.04}{1.96})^2}=425.22$

And rounded up we have that n=426

3 0

2 years ago

A shoe manufacturer compared material A and material B for the soles of shoes. Twelve volunteers each got two shoes. The left wa

sveta [45]

Answer:

a) Are dependent since we are mesuring at the same individuals but on different times and with a different method

b) If we see the qq plot we don't have any significant deviation for the values and we don't have any heavy tail so we can conclude that we can approximate the differences with the normal distribution.

c) $p_v =P(t_{(12)}>0.969) =0.353$

So the p value is higher than the significance level given, so then we can conclude that we FAIL to reject the null hypothesis. So we can conclude that the mean differences is NOT significantly different from 0 .

Step-by-step explanation:

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations (This problem) we can use it.

The Q-Q plot, or quantile-quantile plot, "is a graphical tool to help us assess if a set of data plausibly came from some theoretical distribution such as a Normal or exponential".

Let put some notation

x=value for A , y = value for B

A: 379, 378, 328, 372, 325, 304, 356, 309, 354, 318, 355, 392

B: 372, 376, 328, 368, 283, 252, 369, 321, 379, 303, 328, 411

(a) Are the two samples paired or independent? Explain your answer.

Are dependent since we are mesuring at the same individuals but on different times and with a different method

(b) Make a normal QQ plot of the differences within each pair. Is it reasonable to assume a normal population of differences?

The first step is calculate the difference $d_i=A_i-B_i$ and we obtain this:

d: 7,2,0,4,42,52,-13,-12,-25,15,27,-19

In order to do the qqplot we can use the following R code:

d<-c(7,2,0,4,42,52,-13,-12,-25,15,27,-19)

qqnorm(d)

And the graph obtained is attached.

If we see the qq plot we don't have any significant deviation for the values and we don't have any heavy tail so we can conclude that we can approximate the differences with the normal distribution.

(c) Choose a test appropriate for the hypotheses above and justify your choice based on your answers to parts (a) and (b). Perform the test by computing a p-value, make a test decision, and state your conclusion in the context of the problem

The system of hypothesis for this case are:

Null hypothesis: $\mu_A- \mu_B = 0$