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3 years ago

D. 350.00

Mathematics

2 answers:

Maksim231197 [3]3 years ago

8 0

The answer is B i believe

34kurt3 years ago

5 0

Answer:

B. 7 hours

Step-by-step explanation:

Since the question states "at this rate" , this could be worked out by using simple proportion.

120miles = 3hours

280miles = ?

(280x3)/120 = 7 hours

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A grower believes that one in five of his citrus trees are infected with the citrus red mite. How large a sample should be taken

mihalych1998 [28]

Answer:

n=6147

Step-by-step explanation:

1) Notation and definitions

$X=1$ number of citrus trees that are infected with the citrus red mite.

$n=5$ random sample taken

$\hat p=\frac{1}{5}=0.2$ estimated proportion of citrus trees that are infected with the citrus red mite.

$p$ true population proportion of citrus trees that are infected with the citrus red mite.

Me=0.01 represent the margin of error desired

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".

The population proportion have the following distribution

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

In order to find the critical values 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 values would be given by:

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

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 $ME =\pm 0.01$ 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)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.2(1-0.2)}{(\frac{0.01}{1.96})^2}=6146.56$

And rounded up we have that n=6147

5 0

3 years ago

The jazz band has 13 members. To raise money for a tour, each member sold r raffle tickets. Write an expression that shows the n

Hunter-Best [27]

Answer:

13 * r

Step-by-step explanation:

If each member sells the same number of raffle tickets, then 13r would show that each of the 13 members will have sold r raffle tickets each. The expression is multiplication.

5 0

3 years ago

If natalie and her friends decide to rent 4 lanes at reguler cost for a party ten people need to rent shoes and 4 people are mem

taurus [48]

The question is missing a tabular data. So, it is attached below.

Answer:

The total cost for the party is $74.50.

Step-by-step explanation:

Given:

Lanes rented at regular cost = 4

Cost of 1 lane rented at regular cost = $9.75

Cost of 1 lane rented for members = $7.50