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Calculating the test statistic in a z test for a proportion

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Jake heard that spinning—rather than flipping—a penny raises the probability above 50, percent that the penny lands showing heads. He tests this by spinning 10 different pennies 10 times each, so he's willing to treat these spins as a random sample. In his 100 spins, the penny landed showing "heads" in 68 spins. He wants to use these results to test H, start subscript, 0, end subscript, colon, p, equals, 0, point, 50 versus H, start subscript, start text, a, end text, end subscript, colon, p, is greater than, 0, point, 50, where p is the true proportion of spins that a penny would land showing "heads".
Assuming that the conditions for inference have been met, calculate the test statistic for Jake's significance test.
You may round to two decimal places.
z, equals
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, start text, p, i, end text or 2, slash, 3, space, start text, p, i, end text