Help me help me please

How would the inverse operation of addition be

liraira [26]

Answer:

Step-by-step explanation:

36 + m = 54 subtract 36 from both sides

36 - 36 + m = 54 - 36

m = 54 - 36

m = 18

6 0

2 years ago

Read 2 more answers

In the morning, the number of ducks at the reservoir was 80. By noon, the reservoir had 135 ducks. What was the percent of chang

Mekhanik [1.2K]

Answer:

60 percent

Step-by-step explanation:

number of ducks in morning=80

ducks in after noon=135

for percentage

80/135=0.5925=0.60

0.60*100=60 percent

4 0

2 years ago

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

Each year, more than 2 million people in the United States become infected with bacteria that are resistant to antibiotics. In p

Olegator [25]

Answer:

Reject H₀. There is a significant difference in drug resistance between the two states.

Step-by-step explanation:

In this case we need to determine whether the data suggest a statistically significant difference between the proportions of drug-resistant cases in the two states.

The significance level of the test is, α = 0.02.

(1)

The hypothesis can be defined as follows:

H₀: There is no difference between the proportions of drug-resistant cases in the two states, i.e. $p_{1} - p_{2}= 0$ .

Hₐ: There is a statistically significant difference between the proportions of drug-resistant cases in the two states, i.e. $p_{1} - p_{2}\neq 0$ .