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2 years ago

Factorise and evaluate 50 × 11 + 50 × 9

Mathematics

1 answer:

seropon [69]2 years ago

5 0

Answer:

1000

Step-by-step explanation:

50 × 11 + 50 × 9 ← factor out 50 from each term

= 50(11 + 9)

= 50(20)

= 1000

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Marina CMI [18]

Top Right.
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7 0

3 years ago

Pinky is 5 years older than Rosie. If the sum of their age is 33, find the age of each

astraxan [27]

Answer:

of each what?

Step-by-step explanation:

7 0

3 years ago

A college student is interested in investigating the TV-watching habits of her classmates and surveys 20 people on the number of

Alla [95]

Answer:

80% confidence interval of the true average number of hours of TV watched per week is [8.28 hours, 11.02 hours].

Step-by-step explanation:

We are given that a college student is interested in investigating the TV-watching habits of her classmates and surveys 20 people on the number of hours they watch per week. The results are provided below;

Hours of TV per week (X): 6, 14, 13, 6, 16, 10, 19, 4, 5, 5, 18, 8, 7, 14, 8, 8, 9, 12, 6, 5.

Firstly, the Pivotal quantity for 80% confidence interval for the true average is given by;

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

where, $\bar X$ = sample mean number of hours of TV watched per week = $\frac{\sum X}{n}$ = 9.65

s = sample standard deviation = $\sqrt{\frac{\sum (X -\bar X)^{2} }{n-1} }$ = 4.61

n = sample of people = 20

$\mu$ = true average number of hours of TV watched per week

Here for constructing 80% confidence interval we have used One-sample t-test statistics as we don't know about population standard deviation.

So, 80% confidence interval for the true average, $\mu$ is ;

P(-1.33 < $t_1_9$ < 1.33) = 0.80 {As the critical value of t at 19 degrees of

freedom are -1.33 & 1.33 with P = 10%}

P(-1.33 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.33) = 0.80

P( $-1.33 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.33 \times {\frac{s}{\sqrt{n} } }$ ) = 0.80

P( $\bar X-1.33 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.33 \times {\frac{s}{\sqrt{n} } }$ ) = 0.80

80% confidence interval for $\mu$ = [ $\bar X-1.33 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.33 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $9.65-1.33 \times {\frac{4.61}{\sqrt{20} } }$ , $9.65+1.33 \times {\frac{4.61}{\sqrt{20} } }$ ]

= [8.28 hours, 11.02 hours]

Therefore, 80% confidence interval of the true average number of hours of TV watched per week is [8.28 hours, 11.02 hours].

7 0

3 years ago

Choose the most accurate statement based on the graph shown.

Eddi Din [679]

The most accurate would be the second statement: The graph is misleading because it uses 3-dimensional bars.

The vertical range is just enough. It only appears small because the bars are in 3D. It should have been in 2D so that we could directly trace it to how much frequency each category is. Even the axes are in 3D also.

4 0

3 years ago

Read 2 more answers

8th grade math: Mr. Giles has 6 horses; each horse eats about 85 pounds of feed per year.

LekaFEV [45]

Answer:

510 pounds

Step-by-step explanation:

6x85=510

3 0

4 years ago

Read 2 more answers