2/5 - (-4/3) = what does it equal because im really confused

In a study done by XYZ news found out that the probability of Americans that are left-handed to be 0.11. If 157 Americans are to

aleksley [76]

Answer:

17

Step-by-step explanation:

157*0.11 = 17.27

17 people

3 0

3 years ago

orange jelly beans is 82 and that exam scores have an approximately symmetric distribution. She gives orange jelly beans to 25 r

Ksenya-84 [330]

Answer:

Step-by-step explanation:

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

µ = 82

For the alternative hypothesis,

µ ≠ 82

This is a 2 tailed test

Since the sample mean and sample standard deviation is given, the t test would be used to determine the test statistic. The formula is

t = (x - µ)/(s/√n)

Where

x = sample mean = 87

µ = population mean = 82

s = samples standard deviation = 10

n = 25

t = (87 - 82)/(10/√25) = 2.5

α = 1 - Confidence level

α = 1 - 0.95 = 0.05

Since α = 0.05, the critical value is determined from the t distribution table.

For the left, α/2 = 0.05/2 = 0.025

For the right of 0.025 = 1 - 0.025 = 0.975

To determine the t score from the t distribution table, we would find the degree of freedom, df and look for the corresponding α value.

df = n - 1 = 25 - 1 = 24

t score = critical value = ±2.064

In order to reject the null hypothesis, the test statistic must be smaller than - 2.5 or greater than 2.5

Since - 2.064 > - 2.5 and 2.064 < 2.5, we would fail to reject the null hypothesis.

Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

Margin of error = z × s/√n

Where

s = sample standard deviation

z = t score

Margin of error = 2.064 × 10/√25

= 4.13

Confidence interval = 87 ± 4.13

the lower limit of this confidence interval is

87 - 4.13 = 82.87

the upper limit of this confidence interval is

87 + 4.13 = 91.13

4 0

3 years ago

A bank manager has developed a new system to reduce the time customers spend waiting for teller service during peak hours. The m

Lana71 [14]

Answer:

(a) H₀: μ = 10 vs. Hₐ: μ < 10.

(b) The level of significance is 0.05.

Step-by-step explanation:

A new system is used to reduce the time customers spend waiting for teller service during peak hours at a bank.

A single mean test can be used to determine whether the waiting time has reduced.

(a)

The hypothesis to test whether the new system is effective or not is:

H₀: The mean waiting time is 10 minutes, i.e. μ = 10.

Hₐ: The mean waiting time is less than 10 minutes, i.e. μ < 10.

(b)

The information provided is:

$\bar x=9.5\\s=2.2\\n=70$

Compute the test statistic value as follows:

$t=\frac{\bar x-\mu}{s/\sqrt{n}}=\frac{9.5-10}{2.2/\sqrt{70}}=-1.902$

The test statistic value is t = -1.902.

Compute the p-value of the test as follows:

$p-value=P(t_{n-1}$

$=P(t_{69}1.902)\\=0.031$

The null hypothesis will be rejected if the p-value of the test is less than the significance level (α).

The p-value obtained is 0.031.

To reject the null hypothesis the value of α should be more than 0.031.

The most commonly used values of α are: 0.01, 0.05 and 0.10.

So, the least value of α at which we can conclude that the wait times have decreased is, α = 0.05.

Thus, the level of significance is 0.05.

6 0

4 years ago

This week, Michael collected $468 for delivering newspapers. He had 40 repeat customers and 18 new ones. As an incentive, he cha

artcher [175]

Equation: (Not sure if it's the right order...)

468 = 40x + 18(x - 3)

The fee Micheal charges each suscriber is $6

Work:

468 = 40x + 18(x - 3)

468 = 40x + 18x - 54

Mutilpy 18 & x and 18 & 3

468 = 58x - 54

Add 40x amd 18x

468 + 54 = 58x - 54

Add 54 to 468 to have -54 gone in 58x - 54

522 divide by 58 is 9

x = 9

9 - 3 = 6

7 0

4 years ago

Read 2 more answers

Solve the following equation for p 15p + 5p = 60

frutty [35]

Answer:

I want to say letter c. p=3

5 0

3 years ago