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Define the term ‘infant mortality rate and suggest why ‘infant mortality rate’ is a useful development indicator.

Infant mortality rate is the number of babies who die before the age of one per thousand live births per year. Infant mortality rate shows how countries survival rates vary due different stages of developmen...
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Answered by Polly G. • Geography tutor
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A musical instrument produces a sound wave with a frequency of 1000 Hz. The sound wave has a wavelength of 0.34 m in air. Calculate the speed of the sound wave in air.

From the equation for speed: Speed = frequency * wavelength => v = 1000 * 0.34 = 340 metres per second
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Answered by Laura D. • Physics tutor
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Write down two reasons for using statistical models

There are many reasons for using statistical models. Some examples include: 1) To simplify a real world problem To improve understanding and describe a real world problem, for example understanding the relat...
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Answered by Laura D. • Maths tutor
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The triangle ABC is such that AC=8cm, CB=12cm, angle ACB=x radians. The area of triangle ABC = 20cm^2. Show that x=0.430 (3sf)

From the equation of the area of a triangle, Area = 1/2 AC CB sin(C) 20 = 1/2 * 8 *12 * sin(x) => sin(x) = 0.416666... => x = 0.430 to 3sf
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Answered by Laura D. • Maths tutor
7675 Views

A bag contains 12 bals of different colours: 5 red, 4 blue and 3 yellow. What is the probability of not selecting a red ball

The probability of an event not happening is 1 minus the probability of the event happening. Five of the twelve balls are red so the probability of selecting a red ball is 5/12. The probability of not select...
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Answered by Laura D. • Maths tutor
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