The average monthly cell phone bill was reported to be $50.07 by the u. s. wireless industry. random sampling of a large cell phone company found the following monthly cell phone charges (in dollars): 52.62 46.27 59.77 67.2157.26 49.24 45.99 46.8155.39 48.08at the 0.05 level of significance, can it be concluded that the average phone bill has increased?

The null and alternative hypotheses are:

Under the null hypothesis, the test statistic is:

Where:

is the sample mean

is the sample standard deviation

is the sample size

Now, the right tailed t critical value at 0.05 significance level for df = n-1 = 10-1 = 9 is:

Since the t statistic is less than the t critical value at 0.05 significance level, therefore,we fail to reject the null hypothesis and conclude that there is not sufficient evidence to support the claim that the average phone bill has increased.

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)

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step-by-step explanation: