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3 years ago

Help me please and thank you

Mathematics

1 answer:

Feliz [49]3 years ago

3 0

Answer:

4.2 hours

Step-by-step explanation:

He spends 6 hours helping customers and 1.8 doing paperwork.

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Assume that a sample is used to estimate a population proportion μ . Find the margin of error M.E. that corresponds to a sample

hichkok12 [17]

Answer:

$MoE = 1.645\cdot \frac{13.1}{\sqrt{772} } \\\\MoE = 1.645\cdot 0.47147\\\\MoE = 0.776\\\\$

Step-by-step explanation:

Since the sample size is quite large, we can use the z-distribution.

The margin of error is given by

$MoE = z_{\alpha/2}(\frac{s}{\sqrt{n} } )$

Where n is the sample size, s is the sample standard deviation and $z_{\alpha/2}$ is the z-score corresponding to a 90% confidence level.

The z-score corresponding to a 90% confidence level is

Significance level = α = 1 - 0.90= 0.10/2 = 0.05

From the z-table at α = 0.05

z-score = 1.645

$MoE = 1.645\cdot \frac{13.1}{\sqrt{772} } \\\\MoE = 1.645\cdot 0.47147\\\\MoE = 0.776\\\\$

Therefore, the margin of error is 0.776.

3 0

2 years ago

Which explanation best describes how to solve this problem? Marcia covered her kitchen floor with twice as much tile as her bath

erica [24]

Answer:

54 ft^2

Step-by-step explanation:

Bathroom area is 15 ft^2

The kitchen is twice the bathroom

2*15 = 30 ft^2

Kitchen: 30 ft^2

Front door: 9ft^2

The total is all the areas added together

Total = bathroom + kitchen + front door

= 15 ft^2 + 30 ft^2 + 9 ft^2

= 54 ft^2

7 0

2 years ago

17 points please help me fill it xx

SSSSS [86.1K]

For the very last part, a is 29 and b is 45.

8 0

3 years ago

Read 2 more answers

A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are f

Mnenie [13.5K]

Answer:

A 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC is [0.143, 0.177] .

Step-by-step explanation:

We are given that a researcher randomly selects records from 60 such drivers in 2009 and determines the sample mean BAC to be 0.16 g/dL with a standard deviation of 0.080 g/dL.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean BAC = 0.16 g/dL

s = sample standard deviation = 0.080 g/dL

n = sample of drivers = 60

$\mu$ = population mean BAC in fatal crashes

Here for constructing a 90% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, a 90% confidence interval for the population mean, $\mu$ is;

P(-1.672 < $t_5_9$ < 1.672) = 0.90 {As the critical value of t at 59 degrees of

freedom are -1.672 & 1.672 with P = 5%} P(-1.672 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.672) = 0.90

P( $-1.672 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.672 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

P( $\bar X-1.672 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.672 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

90% confidence interval for $\mu$ = [ $\bar X-1.672 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.672 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $0.16-1.672 \times {\frac{0.08}{\sqrt{60} } }$ , $0.16+1.672 \times {\frac{0.08}{\sqrt{60} } }$ ]

= [0.143, 0.177]

Therefore, a 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC is [0.143, 0.177] .

7 0

3 years ago

Which is an equation of the exponential function that goes through the points (1, 10) and (3, 2.5)? A. y = 20(0.5) x B. y = 20(2

olasank [31]

Answer:

Step-by-step explanation:

Becuase i checked it

7 0

3 years ago

Read 2 more answers