Please help me thank you

Let the abbreviation PSLT stand for the percent of the gross family income that goes into paying state and local taxes. Suppose

gavmur [86]

Answer:

Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.

Step-by-step explanation:

We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.

If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.

Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.

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<u>SO, Margin of error formula is given by;</u>

Margin of error = $Z_(_\frac{\alpha}{2}_ ) \times \frac{\sigma}{\sqrt{n} }$

where, $\alpha$ = significance level = 10%

$\sigma$ = standard deviation = 2.0

n = number of families

Now, in the z table the critical value of x at 5% ( $\frac{0.10}{2} = 0.05$ ) level of significance is 1.645.

SO, Margin of error = $Z_(_\frac{\alpha}{2}_ ) \times \frac{\sigma}{\sqrt{n} }$

0.5 = $1.645 \times \frac{2}{\sqrt{n} }$

$\sqrt{n} =\frac{2\times 1.645 }{0.5}$

$\sqrt{n} =6.58$

n = $6.58^{2}$

= 43.3 ≈ 43

Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.

4 0

3 years ago

Decide whether each table could represent a proportional relationship. If the

Ymorist [56]

Answer:

Step-by-step explanation:

If given tables in the picture show the proportional relationship,

Number of wheels (w) ∝ Number of buses (b)

w ∝ b

w = kb

Here, k = proportionality constant

k = $\frac{w}{b}$

Number of buses (b) Number wheels (w) Wheels per bus $(\frac{w}{b})$

5 30 $\frac{30}{5}=6$

8 48 $\frac{48}{8}=6$

10 60 $\frac{60}{10}=6$

15 90 $\frac{90}{15}=6$

Here, proportionality constant is 6.

Similarly, If number of wheels (w) ∝ Number of train cars (t)

w = kt

Here, k = proportionality constant

k = $\frac{w}{t}$

Number of train cars(t) Number of wheels(w) Wheels per train car ( $\frac{w}{t}$ )

20 184 $\frac{184}{20}=9.2$

30 264 $\frac{264}{30}=8.8$

40 344 $\frac{344}{40}=8.6$

50 424 $\frac{424}{50}=8.48$

Since, ratio of w and t is not constant, relation between number of wheels and number of train cars is not proportional.

5 0

2 years ago

What is the equation of the line that passes through (-3, -1) and has a slope of 3/5? Put your answer in slope-intercept form. y

zubka84 [21]

Answer:

Y=3/5x -4/5

Step-by-step explanation:

3/5 is the slope so you do 3/5x

-4/5 is negative because the line passes two negative coordinates

Hope this helps!

4 0

2 years ago

The mass of Jupiter is 1.898 × 10(27) kilograms, and the mass of Saturn is 5.68 × 10(26) kilograms. How much greater is Jupiter'

grandymaker [24]

Just subtract but take care of the power or else you can come up with wrong results !

so first make the power same ;

for Jupiter = 1.898× 10(27) = 18.98 × 10(26)
for Saturn = 5.68×10(26)

so now subtract = (18.98-5.68) × 10(26)
= 13.3 × 10(26)

so the answer is 13.3 ×10(26)
or, 1.33× 10(27)

6 0

2 years ago

Please help i’m in a hurry

Wittaler [7]

Answer:

the answer should be 18

Step-by-step explanation:

this isnt exactly hard when you get the first part with ST beeing 36 then you can just halve that and the answer is 18

6 0

2 years ago