Statistics professors believe the average number of headaches per semester for all students is more than 18. From a random sample of 15 students, the professors find the mean number of headaches is 19 and the standard deviation is 1.7. Assume the population distribution of number of headaches is normal.

Complete Question

Statistics professors believe the average number of headaches per semester for all students is more than 18. From a random sample of 15 students, the professors find the mean number of headaches is 19 and the standard deviation is 1.7. Assume the population distribution of number of headaches is normal.the correct conclusion at is?

There is no sufficient evidence to support the professor believe

Step-by-step explanation:

From the question we are told that

     The population mean is  

     The sample size is  

      The sample mean is  

      The standard deviation is  

      The level of significance is  

The null hypothesis is  

The  alternative hypothesis is  

 The critical value of the level of significance from the normal distribution table is    

The test hypothesis is mathematically represented as

substituting values  

Looking at the value of  t and   we can see that so we fail to reject the null hypothesis.

This mean that there is no sufficient evidence to support the professor believe

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°